Ragav's Projects

Appearance

Overview ​

Project overview, file map, and research log for the Ant Civilization research dossier.

An independent research project investigating how large ant colonies achieve massive engineering feats through emergent collective behaviour, what their lifecycle looks like, and what their collapses might teach us about civilizational death more broadly.

Why this project exists ​

In May 2026 a popular-press article re-circulated about a Brazilian Atta laevigata nest excavated by pouring 10 tonnes of cement into an abandoned colony. The cast revealed a 3D structure 8 m deep, ~67 m² in lateral extent, with ~1,920 chambers including dedicated fungus farms, waste chambers, and ventilation tunnels arranged into what looks like a thermo-regulating chimney system.

That is a remarkable engineering result for an organism with ~250,000 neurons per individual and no individual that grasps the global plan. It implies the existence of emergent communication and coordination protocols that allow a colony of millions to conceive, share, model, and execute architectural ideas across generations.

This dossier exists to take that observation seriously and follow it across three independent lines of inquiry.

The three core questions ​

This is a long-running research project, not a one-shot report. Each question gets its own file, and each file is built up over multiple sessions.

1. Lifecycle of an ant civilization ​

What happens from the moment a virgin queen takes her mating flight to the moment the colony's last worker dies? What ecosystems do colonies depend on, and which do they themselves construct or stabilise? When do colonies expand, plateau, and senesce, and what are the ecological conditions under which they go extinct? → See Colony Lifecycle.

2. Communication as substitute for individual computation ​

Ants individually have ~250,000 neurons; humans have ~86 billion. Yet ant colonies execute coordinated multi-generational engineering projects that no individual ant could conceive. What communication primitives — chemical, vibrational, tactile, stigmergic — produce this? Is there a literature-grounded set of principles by which a society of low-individual-capacity agents achieves civilizational-scale outputs? And which adjacent fields (collective intelligence, swarm robotics, network science, complex systems) shed the most light on whether human society could be reconfigured to produce proportional breakthroughs? → See Communication.

3. Civilizational death — across species ​

What kills civilizations? The MSN article calls the ant city "abandoned," but the published literature on the A. laevigata cast does not explain why the colony died. Across species — eusocial insects, vertebrates, and human societies — what does the comparative literature on collapse actually say? Which causes recur? Which are species-specific? → See Civilizational Collapse.

These three questions are connected. A complete model of ant civilization needs the lifecycle (when), the communication (how), and the collapse (why it ends). Each file links into the others as the work progresses.

File map ​

FileStatusPurpose
ExcavationsComplete (v1)The physical evidence base. Every primary excavation since Jacoby (1950), with people, institutions, funding, methods, and references. The foundation everything else builds on.
Colony LifecycleStub with reading listWhat happens from queen mating flight to colony death. Ecosystems facilitated and depended on.
CommunicationStub with reading listPheromones, stigmergy, swarm intelligence. Whether the principles transfer to human social design.
Civilizational CollapseStub with reading listCross-species literature on collapse. From Atta to honey bees to human societies.
ReferencesAggregatorMaster bibliography. Auto-grows as files mature.

Methodology and conventions ​

  • Hybrid format. Each topical file opens with a 1-page executive summary that captures the current state of the thread, then drops into long-form sections with citations.
  • Stay grounded. When the literature is solid, we cite it. When we are speculating, we mark the section as such. We do not invent findings or attribute claims to authors who did not make them.
  • Living documents. Files are updated across sessions. Each file has an "Open threads" section at the end where unresolved questions are parked so future sessions can pick them up.
  • Triangulation. Every popular-press claim about ant nest size, age, or behaviour is checked against the primary literature before we use it.

Research log ​

Reverse-chronological. New entries go on top.

2026-05-15 — Project initiated ​

  • Created scaffold (Nextra docs app modelled on clikkin-docs-ui).
  • Wrote excavations.mdx to v1 — comprehensive coverage of Jacoby, Tschinkel, Forti, and Roces lineages, with comparative table and full bibliography.
  • Stubbed lifecycle.mdx, communication.mdx, collapse.mdx with executive scope and initial reading lists.
  • Identified the MSN "underground city" article as the long-running Atta laevigata program at UNESP Botucatu (Forti et al., 2004; Forti et al., 2017). Cast is not a recent discovery; the photographs and findings have been in the literature for two decades and are recycled by popular outlets periodically.
  • Open question: why was the A. laevigata cast nest abandoned? Not explained in the published papers — feeds directly into the collapse file.

Colony Lifecycle ​

From mating flight to colony death — the lifecycle of an ant civilization and the ecosystems it depends on and creates.

Status: stub. Executive scope and reading list complete. Long-form sections to be written in subsequent sessions.

Executive summary (v0) ​

An ant colony is best treated as a superorganism with a definite life history: founding, ergonomic growth, reproductive maturity, senescence, and death. For Atta leafcutters specifically, the cycle is roughly:

  1. Nuptial flight. Once a year, on a warm humid evening after heavy rain, virgin reproductives — alates — emerge from mature colonies. Each virgin queen mates with multiple males in flight, collecting enough sperm in her spermatheca to last her entire reproductive life. Males die shortly after.
  2. Founding. The fertilized queen lands, sheds her wings, digs a small founding chamber, and starts a new fungus garden using a fragment of mycelium she carried in her infrabuccal pocket from her natal colony. Mortality at this stage is brutal — only about 2.5% of founding queens establish a colony that survives the first months. This is the demographic bottleneck that limits Atta densities.
  3. Ergonomic phase. For roughly 3–5 years the colony grows in worker number and nest volume but produces no reproductives. All output goes into infrastructure and the workforce.
  4. Reproductive phase. From roughly year 5 onward a mature colony produces alates each year. The queen continues to lay eggs throughout — possibly 15 to 20 years of continuous egg-laying for Atta.
  5. Senescence and death. When the queen dies, the colony has no replacement (no Atta has functional secondary queens). The existing workers continue for months but are not replenished. The fungus garden, deprived of fresh substrate and worker care, is overrun by parasitic fungi (Escovopsis etc.). The nest is abandoned. The structure persists in the soil as a decaying void — the kind of structure cement-cast excavations exploit.

The colony's relationship to its ecosystem is mutualistic and ecosystem-engineering at the same time. The colony depends on living plant tissue (the leafcutter–fungus mutualism is obligate on both sides) and creates soil structure changes that affect water infiltration, nutrient cycling, and microbial communities for decades after the colony itself is gone. Atta nests are recognised as significant ecosystem engineers in Cerrado and Pantanal biomes.

Planned section outline ​

  1. The superorganism frame. Why colony lifecycle is the right unit of analysis, not individual ant lifespan. Hölldobler & Wilson (2009).
  2. Founding and the bottleneck. Quantitative data on queen mortality from Fowler, Forti, and contemporary work on A. texana and A. cephalotes.
  3. Growth dynamics. Ergonomic vs reproductive phases. How chamber excavation tracks brood and fungus mass (Pinto-Tomás et al. 2014). Metabolic scaling laws for superorganisms (Hou et al. 2010).
  4. Reproductive maturity. Alate production schedules. Demographic implications of single-queen vs polygynous species.
  5. Senescence and queen death. Why Atta colonies are obligately monogynous and what this means for collapse trajectories.
  6. Ecosystem dependencies. The tripartite leafcutter–fungus–bacteria mutualism (Currie et al.). What plants Atta colonies cannot survive without.
  7. Ecosystems Atta colonies create. Soil engineering, hydrology, microbial succession on abandoned nests. The Cerrado/Pantanal context.
  8. Comparative lifecycle data across genera. Atta vs Solenopsis (fire ants — supercolonial) vs Pogonomyrmex vs Formica — different lifecycle architectures.
  9. The "abandoned colony" question. Specifically why the A. laevigata nest in the Botucatu cast was abandoned. Connects to the collapse file.

Initial reading list (sources to consult before writing v1) ​

Primary literature ​

  • Hölldobler, B., & Wilson, E. O. (1990). The Ants. Belknap Press / Harvard UP.
  • Hölldobler, B., & Wilson, E. O. (2009). The Superorganism: The Beauty, Elegance, and Strangeness of Insect Societies. W. W. Norton.
  • Fowler, H. G., et al. (early 1980s onward) — quantitative colony demography for Atta spp.
  • Currie, C. R., Mueller, U. G., & Malloch, D. (1999). The agricultural pathology of ant fungus gardens. PNAS 96(14):7998–8002.
  • Currie, C. R., et al. (2003). Ancient tripartite coevolution in the attine ant–microbe symbiosis. Science 299(5605):386–388.
  • Hou, C., Kaspari, M., Vander Zanden, H. B., & Gillooly, J. F. (2010). Energetic basis of colonial living in social insects. PNAS 107(8):3634–3638.
  • Camargo, R. S., Forti, L. C., et al. (various 2010s–2020s) — colony growth dynamics in Atta bisphaerica, A. capiguara.

Lifecycle-specific ​

  • "Foundress queen mortality and early colony growth of the leafcutter ant, Atta texana" — Insectes Sociaux 2015. PubMed-accessible.
  • "Oviposition, life cycle, and longevity of the leaf-cutting ant Acromyrmex rugosus rugosus" — PMC 5620700.
  • San Diego Zoo Wildlife Alliance / Arizona State University ASU Ask-A-Biologist reference pages — reliable secondary syntheses.

Ecosystem engineering ​

  • Wirth, R., Herz, H., Ryel, R. J., Beyschlag, W., & Hölldobler, B. (2003). Herbivory of Leaf-Cutting Ants: A Case Study on Atta colombica in the Tropical Rainforest of Panama. Springer Ecological Studies 164.
  • Moutinho, P., Nepstad, D. C., & Davidson, E. A. (2003). Influence of leaf-cutting ant nests on secondary forest growth and soil properties in Amazonia. Ecology 84(5):1265–1276.

Open threads ​

  • Why was the A. laevigata Botucatu cast nest abandoned? — chase via Forti lab correspondence or the unpublished field notes if accessible.
  • Mismatch in queen lifespan estimates: 15–20 years (popular sources) vs 20+ years (Hölldobler & Wilson 2009) vs occasional reports of 25+ years. Which is the best-supported number for Atta laevigata specifically?
  • What is the actual annual probability of colony collapse for a mature Atta colony? The founding bottleneck is well-quantified; collapse rates for established colonies are less so.

Communication ​

Pheromones, stigmergy, and swarm intelligence — how colonies of low-individual-capacity agents produce civilizational-scale outputs, and which adjacent fields illuminate whether human society can be similarly configured.

Status: stub. Executive scope, planned outline, and reading list complete. Long-form sections to be written in subsequent sessions. Speculation level: stay grounded in literature (per project convention).

Executive summary (v0) ​

Ant colonies do not have a brain. They have rules running in parallel across millions of low-capacity agents, plus a shared environment that records the rules' outputs. Together these produce coordinated behaviour at scales no individual ant can perceive.

The literature decomposes ant communication into roughly four channels:

  1. Chemical (pheromones). The dominant channel. Trail pheromones, alarm pheromones, recruitment pheromones, queen pheromones, nestmate-recognition cuticular hydrocarbons. Trail pheromones are evaporative, so a "good" trail is rewritten by traffic and a "bad" one decays — this is positive feedback under negative time pressure, which is exactly the mathematical structure of an optimization process.
  2. Stigmergic (environment as memory). Coined by Pierre-Paul Grassé in 1959 for termite mound construction. One agent modifies the environment; another agent reads the modification and responds. No direct agent-to-agent message. The environment is the medium and the memory. Pheromone trails are the simplest case; chamber excavation triggered by the local presence of brood and fungus (Pinto-Tomás et al. 2014) is a structural case.
  3. Vibrational (stridulation). Many ants stridulate — rubbing body segments to produce substrate-borne vibrations that recruit nestmates to a worksite, signal trapped workers, or coordinate fungus-cutting tempo. Less studied than chemical signalling but documented for Atta leafcutters specifically.
  4. Tactile (antennation). Direct body-to-body contact. Trophallaxis (mouth-to-mouth food sharing) doubles as an information channel — chemical messengers in the regurgitate carry colony-state information.

The substitution claim, in its tightest form (Bonabeau, Dorigo, Theraulaz, 1999, Swarm Intelligence: From Natural to Artificial Systems): under the right rule set and the right interaction topology, a sufficiently large population of agents using only local information and stigmergic signalling can perform global computations — shortest-path routing, load balancing, structural optimization — without any agent representing the global state. The colony is the computer.

The transfer to human society — the user's specific question — is the genuinely contested terrain. The literature breaks roughly into:

  • A descriptive school (Hölldobler & Wilson, Sumpter) which says human institutions already exhibit stigmergy: open-source software development, Wikipedia, financial markets, scientific literature. We are already running ant-like protocols when we let environments mediate coordination.
  • A prescriptive school (Surowiecki, Page, Woolley, MIT Center for Collective Intelligence) which asks which configurations of human groups maximize collective intelligence — and finds that diversity of perspective, equality of speaking time, and social sensitivity matter more than individual IQ.
  • A complex-systems school (Santa Fe Institute work; Page, Krakauer, Bettencourt) which formalises civilizational scaling and asks why human cities follow superlinear scaling laws (productivity scales faster than population) while ant colonies follow sublinear ones (per-capita output decreases with size).

The honest synthesis at v0: the substitution of communication-protocol design for raw individual computation is real and well-documented in ants, but the civilizational breakthroughs the user is asking about depend on a richer interaction topology — symbolic representation, generational accumulation of knowledge, institutions that outlive their members — that ants do not have. The relevant fields for the human side are not entomology but collective intelligence research, complex systems / network science, institutional economics, and cognitive science of distributed representation.

Planned section outline ​

  1. Channels. Pheromones (Wilson 1962 onward); stigmergy (Grassé 1959; Theraulaz & Bonabeau 1999); stridulation (Markl, Roces); antennation and trophallaxis.
  2. Stigmergy as the unifying principle. Why "environment as memory" is the deepest abstraction. Heylighen's two-volume synthesis. Hadeli et al.
  3. From signal to computation. Ant Colony Optimization (Dorigo) and what it formally proves about what stigmergic systems can compute. Pheromone-based shortest-path is provably optimal under specific conditions.
  4. Why colony output is more than the sum of ants. Page (2008) on diversity-as-computation. Couzin lab work on collective decision-making in animal groups.
  5. Stigmergy in human systems. Open-source code (Heylighen on Wikipedia and Linux), markets (Hayek's price-signal as stigmergy avant la lettre), scientific literature (Latour, Garfield citation networks).
  6. Collective intelligence research. Woolley et al. (2010, Science) — the "c factor." The MIT Center for Collective Intelligence work. Page's The Difference (2007).
  7. Civilizational scaling. Bettencourt and West on superlinear urban scaling. Why human cities are not ant colonies — and where the analogy breaks. Hou et al. (2010) on why ant colonies are sublinear.
  8. Adjacent fields worth surveying. Network science (Barabási, Newman); complex adaptive systems (Holland, Mitchell); evolutionary cultural transmission (Boyd & Richerson, Henrich); distributed cognition (Hutchins).
  9. What the literature does and does not support about reconfiguring human society for civilizational breakthroughs. A clearly-marked synthesis section, no further than the sources allow.

Initial reading list ​

Foundational ant communication ​

  • Wilson, E. O. (1962). Chemical communication among workers of the fire ant Solenopsis saevissima. Animal Behaviour 10:134–164.
  • Hölldobler, B., & Wilson, E. O. (1990). The Ants. Chapters on communication.
  • Hölldobler, B., & Wilson, E. O. (2009). The Superorganism.

Stigmergy and swarm intelligence ​

  • Grassé, P.-P. (1959). La reconstruction du nid et les coordinations interindividuelles chez Bellicositermes natalensis et Cubitermes sp. Insectes Sociaux 6:41–80. The original stigmergy paper.
  • Theraulaz, G., & Bonabeau, E. (1999). A brief history of stigmergy. Artificial Life 5(2):97–116.
  • Bonabeau, E., Dorigo, M., & Theraulaz, G. (1999). Swarm Intelligence: From Natural to Artificial Systems. Oxford UP.
  • Dorigo, M., & Stützle, T. (2004). Ant Colony Optimization. MIT Press.
  • Heylighen, F. (2016). Stigmergy as a universal coordination mechanism (two-part survey). Cognitive Systems Research 38:4–13 and 50–59.

Collective intelligence (humans) ​

  • Surowiecki, J. (2004). The Wisdom of Crowds. Doubleday.
  • Page, S. E. (2007). The Difference: How the Power of Diversity Creates Better Groups, Firms, Schools, and Societies. Princeton UP.
  • Woolley, A. W., et al. (2010). Evidence for a collective intelligence factor in the performance of human groups. Science 330(6004):686–688.
  • Malone, T. W., & Bernstein, M. S. (eds., 2015). Handbook of Collective Intelligence. MIT Press.

Complex systems and civilizational scaling ​

  • Bettencourt, L. M. A., Lobo, J., Helbing, D., Kühnert, C., & West, G. B. (2007). Growth, innovation, scaling, and the pace of life in cities. PNAS 104(17):7301–7306.
  • West, G. B. (2017). Scale: The Universal Laws of Life, Growth, and Death in Organisms, Cities, and Companies. Penguin.
  • Hou, C., et al. (2010) — see Lifecycle file.
  • Bettencourt, L. M. A. (2013). The origins of scaling in cities. Science 340(6139):1438–1441.

Adjacent disciplines worth surveying ​

  • Hutchins, E. (1995). Cognition in the Wild. MIT Press. (distributed cognition)
  • Boyd, R., & Richerson, P. J. (1985 / 2005). The Origin and Evolution of Cultures. OUP.
  • Henrich, J. (2015). The Secret of Our Success. Princeton UP.
  • Couzin, I. D. lab work on collective animal behaviour — multiple Science / Nature papers.
  • Theraulaz, G. lab on insect collective behaviour, CNRS Toulouse.

Specifically on stigmergy in human systems ​

  • Heylighen, F. (2007). Why is open access development so successful? Stigmergic organization and the economics of information.
  • Marsh, L., & Onof, C. (2008). Stigmergic epistemology, stigmergic cognition. Cognitive Systems Research 9(1–2):136–149.

Open threads ​

  • Whether Atta specifically uses stridulation in fungus-cutting tempo coordination, and whether this has been rigorously measured. Roces and colleagues have early work but the literature is thin.
  • The "c factor" (collective intelligence factor in human groups) — how robust is the original Woolley et al. result? Replication status.
  • Bettencourt/West superlinear-scaling work — what are the strongest counter-arguments? The work is heavily cited but not uncontested.
  • Whether any rigorous formal mapping has been published between Dorigo's ACO algorithms and human institutional design. Suspect not — but worth confirming.
  • The "civilizational breakthrough" framing in the user's prompt is non-standard in the literature. Need to translate it into a researchable form (e.g., "what configurations maximize the rate of cumulative cultural innovation?") before v1.

Excavations ​

A literature-grounded survey of the major ant-nest excavations — methods, findings, and the people behind them.

First task of this research project. Catalog the major scientific excavations of large ant nests, the people and institutions who did them, the methods, the headline findings, and every published reference that came out of those programs. This file is the foundation; downstream files (lifecycle, communication, collapse) draw their physical evidence from here.

Executive summary ​

Three independent research programs over the past 70 years are responsible for almost everything we know about the internal architecture of large ant nests:

  1. Jacoby (1935–1955), Brazil — the methodological pioneer. Exposed Atta sexdens rubropilosa nests by direct excavation, then in 1950 became the first to pour cement into a nest to create a solid cast. Every subsequent "concrete cast" excavation descends from this method.
  2. Walter R. Tschinkel (1990s–present), Florida State University — formalized the plaster, wax, and molten-metal casting method into a reproducible field technique. Cast hundreds of nests across dozens of species (Pogonomyrmex badius, Solenopsis invicta, Aphaenogaster, Formica, Pheidole, etc.). Synthesized in his 2021 book Ant Architecture.
  3. Luiz Carlos Forti and collaborators (1990s–present), UNESP Botucatu, Brazil — scaled the cement-casting method to giant leafcutter nests. Their 10-tonne Atta laevigata concrete cast — the one popularized by the MSN article that prompted this research — produced a nest model 8 m deep, 67 m² in lateral extent, with 1,920 chambers including 238 fungus chambers. A parallel German–Argentine line led by Flavio Roces (Universität Würzburg) studies the closely related Atta vollenweideri in the Chaco, with a focus on ventilation, CO₂ regulation, and digging behavior.

The research is unified by one question: how does a colony with no central planner and no individual that grasps the whole, nonetheless build a structure whose spatial logic — fungus chambers separated from waste chambers, peripheral inflow tunnels feeding a central exhaust chimney, top-heavy chamber distribution — looks like the work of a civil engineer? The Forti and Roces programs frame this explicitly as a question about emergent functional architecture; Tschinkel frames it as the question of whether ants follow species-specific "architectural plans" or are responding to local cues that produce convergent shapes.

The headline excavation that triggered this project — sometimes captioned in popular press as a "hidden underground city" — is not a recent discovery. It is the long-running Atta laevigata program out of UNESP Botucatu, with field work going back to the late 1990s. The MSN article and similar pieces in 2024–2026 are popular-press reframings of work already published in Studies on Neotropical Fauna and Environment (2004) and Insects (2017). What is genuinely scientifically interesting is not the existence of the cast — that is a known result — but the engineering interpretation it permits.

Status of this file. Comprehensive on the three programs above. Gaps to fill in later sessions: (1) Jacoby's original Portuguese-language papers (only known via secondary citation here); (2) the full Roces/Würzburg publication list; (3) Asian and African leafcutter / fungus-growing ant nest casts (currently unrepresented); (4) primary funding figures from FAPESP and CNPq grant databases.

1. The Brazilian Atta laevigata excavation (the trigger story) ​

The MSN piece, the LADbible series, and several other 2024–2026 popular-science articles all describe the same field operation: a research team in Brazil pours roughly 10 tonnes of liquid cement into an abandoned giant ant nest, waits ten days for it to set, then excavates the surrounding earth to expose a 3D model of the nest interior. The exposed cast is reported to extend roughly 8 metres deep, span roughly 67 m² laterally, and contain on the order of 1,900 chambers including a few hundred fungus-garden chambers. The research was led by Prof. Luiz Carlos Forti at the Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Botucatu campus, in the Laboratório de Insetos Sociais-Praga within the Faculdade de Ciências Agronômicas (FCA).

Two things matter that the popular pieces obscure:

  • The cast is not new. The Atta laevigata cast and its quantitative description were published in 2004 (Moreira, Forti et al., Studies on Neotropical Fauna and Environment 39:2, pp. 109–116). The dramatic photographs that circulate online have been around for two decades; they go viral periodically as new outlets discover them.
  • The colony was already abandoned. This is critical to the ethics and the science. The cement is poured into a dead nest — a colony that had already collapsed for unrelated reasons — so the excavation does not kill millions of ants. The "abandoned" framing in the MSN headline is not a mystery to be solved; it is a precondition for the study.

What was actually found ​

Quantitatively, Moreira, Forti, et al. (2004) studied three nests of Atta laevigata in Botucatu, São Paulo. Two were exposed by direct excavation and mapping; the third was cement-moulded for 3D visualization. Headline numbers from the paper and its successors:

QuantityRange / value
Number of chambers per nest1,149 to 7,864
Maximum depthup to 7 m below grade (some popular reports cite 8 m)
Lateral extent of the cast nesttens of m² (the often-quoted 67 m² is for the cement cast nest specifically)
Estimated soil moved during the colony's lifetimeup to ~40 tonnes (this figure originates with Atta sexdens and is extrapolated to A. laevigata; see §4)
Fungus chambers (in the cast nest)~238
Surface moundconical, multi-entrance, with foraging tunnels radiating to leaf-collection sites

Atta laevigata nests are, by these measurements, the deepest within the genus Atta and contain the highest number of chambers so far recorded for the genus. The species has therefore become the de facto model organism for studying scale limits in eusocial nest construction.

Engineering interpretation ​

The interpretive layer — the part that makes this interesting beyond "wow, big hole" — comes from later analyses by the same group and from comparative work on A. vollenweideri (next section). The two key claims:

  • Thermo-regulatory ventilation (the "chimney effect"). Tunnels are not arranged randomly. Upper-central tunnels function as outflow pathways; lower-peripheral tunnels function as inflow. Heat generated by the millions of metabolizing ants and by the fungus gardens drives a convection current up through the central chimney; surface wind across the central turret pulls additional warm/CO₂-laden air out, which draws fresh air in through the peripheral inflows. Roces and colleagues showed for A. vollenweideri that this is a true wind-induced ventilation system — the first such mechanism described for a social insect colony (Kleineidam, Ernst, & Roces, 2001, Naturwissenschaften 88:7).
  • Pathogen segregation. Waste chambers are placed at the periphery or bottom of the nest, structurally separated from the fungus gardens. Forti, Andrade et al. (2017) showed for A. capiguara that the total volume of waste chambers is proportional to the total volume of fungus chambers — i.e. the colony scales its sanitation infrastructure to match its production infrastructure. This is functional architecture by any reasonable definition.

People, institutions, funding ​

  • Principal investigator: Prof. Luiz Carlos Forti, UNESP Botucatu, FCA, Departamento de Produção Vegetal.
  • Lab: Laboratório de Insetos Sociais-Praga (LISP).
  • Key collaborators on these papers: Sandra H. Moreira, Roberto da Silva Camargo, Nadia Caldato, Nilson S. Nagamoto, Carlos A. O. de Matos, José Cola Zanuncio, and others across UNESP campuses and partner institutions in Brazil and Germany.
  • Funding: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) — Forti held grant 301917/2009-4 covering this research line — and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), which lists multiple Forti grants in its public database (bv.fapesp.br/en/pesquisador/5969). Brazilian leafcutter research is also institutionally relevant to agribusiness pest control because Atta species are major defoliators of eucalyptus plantations — this is the stated applied agenda that secures continued funding alongside the basic-science publications.

Stated thesis / agenda ​

The published agenda of the Forti program, as readable across the abstracts and discussion sections of the 2004, 2017, and 2020 papers, has three interlocking components:

  1. Document. Quantitatively characterize the architecture of giant Atta nests across species (A. laevigata, A. capiguara, A. bisphaerica, A. sexdens rubropilosa) so that comparative claims become possible. This was largely missing before the program began — most prior literature was anecdotal or single-species.
  2. Explain. Identify the rules by which workers construct the architecture, given that no individual ant has access to the global plan. Forti's 2014 work and later collaborations explore how relocating brood and fungus triggers the excavation of new chambers — i.e., the architecture is built by local stigmergic responses to the presence of fungus and brood, not by a global blueprint (Pinto-Tomás et al.; see §5 for the PLOS ONE citation).
  3. Apply. Translate the architectural understanding into better leafcutter pest control — specifically, into more effective chemical-bait targeting of fungus chambers and into agronomic practices that disrupt nest expansion.

The second component — emergent architecture from local rules — is the thesis that makes ant nests interesting as a model for the broader research questions in this project (communication, civilizational scaling).

2. The methodological lineage ​

The "pour something in, dig it out" technique looks simple but took half a century to mature. The lineage is worth recording because it explains why the Atta laevigata cast looks the way it does — it inherits design choices from earlier generations.

Jacoby (1935–1955) — the inventor ​

The Brazilian entomologist Martin Jacoby is credited as the originator of cement casting for ant nests. His 1955 paper for Atta sexdens rubropilosa is the first systematic exposure of a giant Atta nest interior. He had reported the cement-moulding technique itself in 1950. Jacoby's work is published in Portuguese-language journals and is now hard to retrieve outside Brazilian libraries, but every modern Atta nest paper opens by citing him. Gap in this dossier: the original Jacoby papers themselves are not yet in our reference list — to be located via UNESP library or SciELO Brasil retrospective digitization.

Tschinkel (1990s–present) — the systematizer ​

Walter R. Tschinkel, professor emeritus at Florida State University, took the casting technique and turned it into a reproducible scientific method applicable to dozens of ant species. His innovations:

  • Dental plaster (Williams & Lofgren 1988; Tschinkel adopted and refined) for nests too small for cement — gives a much higher-resolution cast.
  • Molten paraffin wax and aluminium / zinc for nests of intermediate size, with the metal casts being striking enough to enter popular consciousness through Bert Hölldobler's photography.
  • Censusing protocol. Casting alone gives shape; Tschinkel's protocol additionally requires collecting and counting all the chambers' contents (workers, brood, seeds, fungus, refuse) to map vertical distribution of colony function.

His most cited single nest study is "The nest architecture of the Florida harvester ant, Pogonomyrmex badius" (Tschinkel, 2004, Journal of Insect Science 4:21), which established the now-standard descriptive vocabulary: shafts (descending, helical, 4–6 cm diameter, 15°–70° angle) and chambers (horizontal, top-heavy distribution). The book Ant Architecture: The Wonder, Beauty, and Science of Underground Nests (Princeton University Press, 2021; PROSE Award winner) is the definitive synthesis.

Forti and Roces (2000s–present) — the scalers ​

The Forti program in Brazil and the Roces program in Germany–Argentina are the two labs that took the casting method to the giant nests of leafcutter ants, where the cast can weigh 10 tonnes and a single nest can house 5–8 million ants. These are the only nests in the world that can plausibly be described as "underground cities" without exaggeration. Both programs publish actively; both treat the casts as raw data for an architectural-emergence research question rather than as endpoints.

3. Comparative table of major published nest excavations ​

YearLead authorsSpeciesSiteMethodHeadline measurementsKey citation
1950JacobyAtta sexdens rubropilosaBrazilFirst cement cast(qualitative)Jacoby, 1950 (in Portuguese)
1955JacobyAtta sexdens rubropilosaBrazilDirect excavation + cementFirst systematic chamber count for giant AttaJacoby, 1955
1988Williams & LofgrenSolenopsis invicta (fire ant)USA, FloridaDental plasterIntroduced plaster methodWilliams & Lofgren, 1988
2001Kleineidam, Ernst & RocesAtta vollenweideriArgentine ChacoDirect excavation + ventilation measurementFirst documented wind-induced nest ventilationNaturwissenschaften 88(7):301–305
2004Moreira, Forti et al.Atta laevigataBotucatu, SP, BrazilCement cast + direct excavation1,149–7,864 chambers; up to 7 m depth; cast nest 67 m²Stud. Neotrop. Fauna Environ. 39(2):109–116
2004TschinkelPogonomyrmex badiusFlorida, USAPlaster cast + censusEstablished the helical-shaft / horizontal-chamber vocabularyJ. Insect Sci. 4:21
2006MoserAtta texanaLouisiana, USAComplete excavation + mappingFirst fully mapped A. texana nest in the US SouthAnn. Entomol. Soc. Am. 99(5):891–897
2011Halboth & RocesAtta vollenweideriArgentine ChacoLab + field — turret constructionMaterial selection rules for ventilation turret assemblyJ. Insect Behav. 25:296–310
2014Pinto-Tomás et al. (Roces lab)A. vollenweideriLabBrood/fungus relocation experimentsNew chambers excavated where brood/fungus are placed — local stigmergic triggerPLOS ONE 9(5):e97872
2017Forti, Andrade, Camargo, Caldato & MoreiraAtta capiguaraSão Paulo, BrazilCement castFungus chambers 6.0 ± 2.0 m from mound; waste chamber volume proportional to fungus chamber volumeInsects 8(2):39
2017Halboth & RocesA. vollenweideriLabTurret construction under varying CO₂CO₂ levels (not airflow or humidity) drive turret structurePLOS ONE 12(11):e0188162
2020Camargo, Forti et al.Atta bisphaericaBrazilField excavationArchitecture and colony growth across colony ageSociobiology / related — PubMed 33137875
2021TschinkelMultipleUSA + lit. reviewSynthesisBook-length comparative architecturePrinceton UP, ISBN 9780691179315

The picture this table paints: everything we quantitatively know about the inside of a giant ant nest comes from fewer than a dozen labs, and most of it from two — Forti's at UNESP and Roces's at Würzburg. This concentration matters; it shapes which species we have data for and which we don't.

4. The 40-tonne soil-movement figure ​

Almost every popular article on Atta nests asserts that the colony "moved 40 tonnes of soil" over its lifetime. This figure deserves an honest provenance note because it travels independently of any single excavation.

The original 40-tonne estimate is for Atta sexdens, not A. laevigata. It comes from the older Brazilian literature (frequently cited to Autuori, 1942 / 1947 in the Brazilian Arquivos do Instituto Biológico) and was reaffirmed in Hölldobler & Wilson's The Ants (1990) and The Superorganism (2009). The arithmetic is: a mature A. sexdens mound averages roughly 40 m³ of excavated material at the surface, and the underground voids add perhaps another 20 m³; converting volume to mass at typical Cerrado soil density yields the round-number 40 tonnes.

The A. laevigata cast is comparable in scale to A. sexdens — possibly larger in depth — but the 40-tonne figure attached to it in popular pieces is borrowed, not independently measured. Treat it as an order-of-magnitude estimate, not a direct measurement of the cast nest.

5. Key references ​

This is the working bibliography for the excavations file. Citations are organized chronologically within each program. Where DOIs or stable URLs are known, they are included; where only the secondary citation is reliable, that is noted.

Jacoby — methodological origin ​

  • Jacoby, M. (1950). A new method for studying the cuttings of Atta sexdens rubropilosa Forel. Brazilian entomological literature; original Portuguese, citation incomplete pending library retrieval. Gap.
  • Jacoby, M. (1955). Estudo sobre a digestão dos sauveiros de Atta sexdens rubropilosa. Brazilian Ministry of Agriculture publications. Gap — full citation pending.

Tschinkel — Florida State University ​

  • Williams, D. F., & Lofgren, C. S. (1988). Nest casting of some ground-dwelling Florida ant species using dental labstone. In Advances in Myrmecology (Trager, ed.), pp. 433–443. Brill.
  • Tschinkel, W. R. (2004). The nest architecture of the Florida harvester ant, Pogonomyrmex badius. Journal of Insect Science 4(1):21. https://academic.oup.com/jinsectscience/article/4/1/21/886534
  • Tschinkel, W. R. (2017). Lifetime nest excavation and contents of mature colonies of Pogonomyrmex badius. Ecology (the "Scientific Naturalist" series).
  • Tschinkel, W. R. (2021). Ant Architecture: The Wonder, Beauty, and Science of Underground Nests. Princeton University Press. ISBN 978-0-691-17931-5.

Forti — UNESP Botucatu ​

Roces — Universität Würzburg ​

Other excavations cited above ​

Synthesis works ​

  • Hölldobler, B., & Wilson, E. O. (1990). The Ants. Belknap Press of Harvard UP.
  • Hölldobler, B., & Wilson, E. O. (2009). The Superorganism. W. W. Norton.
  • LADbible (2024-08-27, 2024-01-19, 2026-03-12): "Scientists discovered hidden mega-city after pouring tonnes of cement into abandoned ant hill" and reposts.
  • MSN / inkl: "Hidden underground 'city' built by ants discovered in Brazil after shocking concrete test" (re-aggregated multiple times; the AA22mAnx URL the user shared is one of these).
  • ClickPetróleoeGás: "Scientists pour 10 tons of cement into an abandoned anthill in Brazil and reveal an 'underground city'..."
  • medtigo: "Discovery of a Lost Underground Ant City in Brazil"
  • YouTube: "Secret Megalopolis of Ants Uncovered" (re-uses the original Forti footage).

6. Open threads to investigate later ​

These are deliberately not closed off — flagging them here so future sessions can pick up.

  • Jacoby's original Portuguese papers. Need to retrieve from UNESP library / SciELO Brasil retrospective digitization. The methodological lineage is incomplete without them.
  • Funding figures. FAPESP and CNPq grant amounts and date ranges are publicly searchable but I have only summary references here. Worth pulling if we want to assess how much money has actually been spent on this research line over 30 years.
  • Asian / African fungus-growing ants. The literature is heavily Atta-centric. Macrotermes termite mounds (very different organism, similar engineering question) are the obvious comparison case and are not covered here.
  • Turner, J. Scott — The Tinkerer's Accomplice (Harvard UP, 2007). Cross-species treatment of "extended physiology" and how organisms construct their environments. Should be added when we open the communication and lifecycle files.
  • Comparative architecture across the Atta genus. A consolidated table of A. sexdens, A. laevigata, A. capiguara, A. bisphaerica, A. vollenweideri, A. cephalotes with measurements would be a natural next deliverable inside this file.
  • The "civilization went extinct" framing. Why this Atta laevigata nest was abandoned is not explained in the published papers — it is taken as a precondition. Worth chasing because the user's lifecycle and collapse questions both depend on it.

Civilizational Collapse ​

Why civilizations end — across ant colonies, eusocial insects, vertebrate societies, and human civilizations.

Status: stub. Executive scope, planned outline, and reading list complete. Long-form sections to be written in subsequent sessions.

Executive summary (v0) ​

"Civilizational death" is not one phenomenon. The comparative literature distinguishes at least four mechanistically distinct classes of collapse:

  1. Reproductive failure. The system loses its capacity to replenish itself. For obligately monogynous Atta leafcutters, queen death = colony death; the workers continue but cannot be replaced. For honey bees in Colony Collapse Disorder (CCD), the workforce abandons the hive while a queen and brood remain — same structural endpoint (no replenishment), different proximate mechanism. For human populations, sub-replacement fertility is the analogous case (slow rather than catastrophic).
  2. Pathogen-driven collapse. Tightly integrated social organisms are vulnerable to pathogens that exploit the integration. The CCD literature implicates Nosema ceranae in combination with viruses; the invasive-ant literature documents pathogen-mediated collapses of Linepithema humile supercolonies (Cooling et al.); human civilization has the Antonine plague, the Black Death, and indigenous-American collapse following European contact as the canonical cases.
  3. Resource exhaustion / ecological mismatch. The system depletes the resources it depends on, or its environment changes faster than it can adapt. Tainter's The Collapse of Complex Societies (1988) is the foundational treatment for human cases; Diamond's Collapse (2005) the most popular. For social insects, this manifests as a colony exhausting forage radius without the capacity to relocate, or a fungus-growing colony losing its cultivar to a parasite. The MSN article's A. laevigata nest is described as "abandoned" — most likely a resource-mismatch or pathogen-mediated collapse, but the published papers do not say.
  4. Internal complexity overhead. Tainter's specific thesis: societies invest in solving problems by adding complexity; complexity has accelerating marginal costs and decelerating marginal returns; eventually the marginal return on additional complexity goes negative and the system simplifies — sometimes catastrophically. The biological analogue is being explored under the heading of diseconomies of social scale.

To these the literature increasingly adds a fifth, hybrid class — cascade failures in tightly coupled systems where any of the above four can trigger any of the others. Tainter, Diamond, and Bardi (Sustainable Energy Transitions, 2017) all converge on this picture: collapse is rarely monocausal at the scale that matters; it is a regime shift in a complex adaptive system.

The Atta case — abandoned underground city in Brazil — sits at the intersection of (1) and (3): queen senescence in an environment whose resource base may have been changing. The published literature does not commit to a cause, which is itself instructive: most extinct ant colonies do not have a written cause of death, much like most extinct human civilizations.

Planned section outline ​

  1. Defining "collapse." Why the word is contested. Tainter's definition (sudden simplification of a sociopolitical system) vs Diamond's (drastic decrease in human population size and/or political/economic/social complexity) vs the ecology literature's regime-shift framing.
  2. Reproductive failure as the cleanest case. Atta queen death; honey bee CCD; demographic collapse of supercolonies; sub-replacement human fertility.
  3. Pathogen-driven collapse. Why social integration is a disease vector. Cooling et al. (2022) on natural and manipulated collapse of invasive Argentine ants. CCD literature. The Black Death and post-Columbian American collapses.
  4. Resource exhaustion and ecological mismatch. Easter Island as the canonical (and contested) case. The Anasazi / Ancestral Puebloan case. Atta foraging collapse cases.
  5. Tainter's complexity-cost thesis. The 1988 argument in detail. What kinds of complexity have the worst returns. Why the thesis applies to non-human social systems.
  6. Cascade failures. Bardi, Brian Walker, "Adaptive cycles" (Holling). The C. S. Holling adaptive-cycle framework as a unifying language.
  7. What ant collapses tell us about human collapses. The honest synthesis. The disanalogies are as important as the analogies (no symbolic representation, no institutional memory, no possibility of reform).
  8. Specifically: why was the Botucatu A. laevigata nest abandoned? What can be inferred from the cast itself — chamber occupancy at time of death, refuse-chamber state, ventilation-tunnel collapse patterns. Open question.

Initial reading list ​

Foundational on collapse (human civilizations) ​

  • Tainter, J. A. (1988). The Collapse of Complex Societies. Cambridge UP.
  • Diamond, J. (2005). Collapse: How Societies Choose to Fail or Succeed. Viking. (Use carefully — the Easter Island and Greenland chapters are contested in the archaeological literature.)
  • McAnany, P. A., & Yoffee, N. (eds., 2009). Questioning Collapse. Cambridge UP. (The corrective to Diamond — read alongside.)
  • Turchin, P. (2003). Historical Dynamics: Why States Rise and Fall. Princeton UP.
  • Turchin, P., & Nefedov, S. A. (2009). Secular Cycles. Princeton UP.

Eusocial insect collapse ​

  • vanEngelsdorp, D., & Meixner, M. D. (2010). A historical review of managed honey bee populations in Europe and the United States and the factors that may affect them. Journal of Invertebrate Pathology 103:S80–S95.
  • Cox-Foster, D. L., et al. (2007). A metagenomic survey of microbes in honey bee colony collapse disorder. Science 318(5848):283–287.
  • Cooling, M., et al. (2022). Pathogen-mediated natural and manipulated population collapse in an invasive social insect. PNAS / PMC 9168452.
  • Wikipedia overview of colony collapse disorder — useful as a literature map only.

Insect decline more broadly (the macro context) ​

  • Wagner, D. L., et al. (2021). Insect decline in the Anthropocene: Death by a thousand cuts. PNAS 118(2):e2023989118.
  • Sánchez-Bayo, F., & Wyckhuys, K. A. G. (2019). Worldwide decline of the entomofauna: A review of its drivers. Biological Conservation 232:8–27.

Superorganism framing ​

  • Hou, C., Kaspari, M., Vander Zanden, H. B., & Gillooly, J. F. (2010). Energetic basis of colonial living in social insects. PNAS 107(8):3634–3638. PMC 2928319.
  • Hölldobler, B., & Wilson, E. O. (2009). The Superorganism.

Resilience and adaptive cycles (cross-system framework) ​

  • Holling, C. S. (2001). Understanding the complexity of economic, ecological, and social systems. Ecosystems 4(5):390–405.
  • Walker, B., et al. (2004). Resilience, adaptability and transformability in social–ecological systems. Ecology and Society 9(2):5.
  • Gunderson, L. H., & Holling, C. S. (eds., 2002). Panarchy: Understanding Transformations in Human and Natural Systems. Island Press.

Ant-specific collapse data ​

  • Pielström, S., & Roces, F. (2014). Soil moisture and excavation behaviour in Atta vollenweideri — implicit data on environmental drivers of nest abandonment.
  • Forti lab papers (see Excavations file) — implicit data on colony-age distributions in Atta populations.

Open threads ​

  • The most important open question for this project: why was the Botucatu A. laevigata cast nest abandoned? Forti's papers do not commit. This is the lifecycle/collapse linkage point.
  • Are there any rigorous studies of annual collapse rates of mature Atta colonies in undisturbed habitat? (Studies in eucalyptus plantations do not count — the colonies are being killed by humans.)
  • Tainter's thesis was developed for human societies. Has anyone formally applied it to social insect collapses? Suspect not — would be a publishable synthesis.
  • The Diamond–McAnany & Yoffee debate is foundational to the human side. v1 needs a clean section on what is and is not contested.
  • Connection to dark forest / great filter discourses (Hanson's Great Filter, Bostrom). These are speculative but adjacent and worth at least a paragraph noting why they sit outside this dossier's scope.

References ​

Master bibliography aggregated across all files in this dossier.

Aggregator file. Collated from the per-topic files. As topical files mature, the canonical citation list lives in those files; this page should be regenerated periodically. Last regenerated: 2026-05-15.

Excavations and nest architecture ​

  • Williams, D. F., & Lofgren, C. S. (1988). Nest casting of some ground-dwelling Florida ant species using dental labstone. In Trager (ed.), Advances in Myrmecology, pp. 433–443. Brill.
  • Kleineidam, C., Ernst, R., & Roces, F. (2001). Wind-induced ventilation of the giant nests of the leaf-cutting ant Atta vollenweideri. Naturwissenschaften 88(7):301–305. https://link.springer.com/article/10.1007/s001140100235
  • Moreira, A. A., Forti, L. C., Andrade, A. P. P., Boaretto, M. A. C., & Lopes, J. F. S. (2004). Nest architecture of Atta laevigata (F. Smith, 1858) (Hymenoptera: Formicidae). Studies on Neotropical Fauna and Environment 39(2):109–116.
  • Tschinkel, W. R. (2004). The nest architecture of the Florida harvester ant, Pogonomyrmex badius. Journal of Insect Science 4(1):21. https://academic.oup.com/jinsectscience/article/4/1/21/886534
  • Moser, J. C. (2006). Complete excavation and mapping of a Texas leafcutting ant nest. Annals of the Entomological Society of America 99(5):891–897.
  • Halboth, F., & Roces, F. (2011). The construction of turrets for nest ventilation in the grass-cutting ant Atta vollenweideri. J. Insect Behav. 25:296–310.
  • Pinto-Tomás, A. A., et al. (2014). Nest enlargement in leaf-cutting ants: relocated brood and fungus trigger the excavation of new chambers. PLOS ONE 9(5):e97872.
  • Pielström, S., & Roces, F. (2014). Soil moisture and excavation behaviour in the Chaco leaf-cutting ant (Atta vollenweideri). PMC 3991694.
  • Forti, L. C., Andrade, A. P. P., Camargo, R. S., Caldato, N., & Moreira, A. A. (2017). Discovering the giant nest architecture of grass-cutting ants, Atta capiguara (Hymenoptera, Formicidae). Insects 8(2):39. https://www.mdpi.com/2075-4450/8/2/39
  • Halboth, F., & Roces, F. (2017). The construction of ventilation turrets in Atta vollenweideri leaf-cutting ants: CO₂ levels in nest tunnels influence turret structure. PLOS ONE 12(11):e0188162.
  • Tschinkel, W. R. (2017). Lifetime nest excavation and contents of mature colonies of Pogonomyrmex badius. Ecology (Scientific Naturalist).
  • Camargo, R. S., et al. (2020). Nest architecture and colony growth of Atta bisphaerica grass-cutting ants. PubMed 33137875.
  • Tschinkel, W. R. (2021). Ant Architecture: The Wonder, Beauty, and Science of Underground Nests. Princeton UP. ISBN 978-0-691-17931-5.
  • Jacoby, M. (1950, 1955). Original Brazilian-Portuguese papers on cement-cast methodology and Atta sexdens rubropilosa nest excavation. Citation incomplete — gap.

Communication, stigmergy, swarm intelligence ​

  • Grassé, P.-P. (1959). La reconstruction du nid et les coordinations interindividuelles chez Bellicositermes natalensis et Cubitermes sp. Insectes Sociaux 6:41–80.
  • Wilson, E. O. (1962). Chemical communication among workers of the fire ant Solenopsis saevissima. Animal Behaviour 10:134–164.
  • Theraulaz, G., & Bonabeau, E. (1999). A brief history of stigmergy. Artificial Life 5(2):97–116.
  • Bonabeau, E., Dorigo, M., & Theraulaz, G. (1999). Swarm Intelligence: From Natural to Artificial Systems. Oxford UP.
  • Dorigo, M., & Stützle, T. (2004). Ant Colony Optimization. MIT Press.
  • Heylighen, F. (2016). Stigmergy as a universal coordination mechanism (two-part survey). Cognitive Systems Research 38:4–13 and 50–59.
  • Marsh, L., & Onof, C. (2008). Stigmergic epistemology, stigmergic cognition. Cognitive Systems Research 9(1–2):136–149.

Collective intelligence and complex systems ​

  • Surowiecki, J. (2004). The Wisdom of Crowds. Doubleday.
  • Page, S. E. (2007). The Difference. Princeton UP.
  • Bettencourt, L. M. A., Lobo, J., Helbing, D., Kühnert, C., & West, G. B. (2007). Growth, innovation, scaling, and the pace of life in cities. PNAS 104(17):7301–7306.
  • Woolley, A. W., et al. (2010). Evidence for a collective intelligence factor in the performance of human groups. Science 330(6004):686–688.
  • Bettencourt, L. M. A. (2013). The origins of scaling in cities. Science 340(6139):1438–1441.
  • Malone, T. W., & Bernstein, M. S. (eds., 2015). Handbook of Collective Intelligence. MIT Press.
  • West, G. B. (2017). Scale. Penguin.
  • Hutchins, E. (1995). Cognition in the Wild. MIT Press.
  • Henrich, J. (2015). The Secret of Our Success. Princeton UP.
  • Boyd, R., & Richerson, P. J. (2005). The Origin and Evolution of Cultures. OUP.

Lifecycle, superorganism biology, ecology ​

  • Hölldobler, B., & Wilson, E. O. (1990). The Ants. Belknap / Harvard UP.
  • Hölldobler, B., & Wilson, E. O. (2009). The Superorganism. W. W. Norton.
  • Currie, C. R., Mueller, U. G., & Malloch, D. (1999). The agricultural pathology of ant fungus gardens. PNAS 96(14):7998–8002.
  • Currie, C. R., et al. (2003). Ancient tripartite coevolution in the attine ant–microbe symbiosis. Science 299(5605):386–388.
  • Wirth, R., Herz, H., Ryel, R. J., Beyschlag, W., & Hölldobler, B. (2003). Herbivory of Leaf-Cutting Ants. Springer Ecological Studies 164.
  • Moutinho, P., Nepstad, D. C., & Davidson, E. A. (2003). Influence of leaf-cutting ant nests on secondary forest growth and soil properties in Amazonia. Ecology 84(5):1265–1276.
  • Hou, C., Kaspari, M., Vander Zanden, H. B., & Gillooly, J. F. (2010). Energetic basis of colonial living in social insects. PNAS 107(8):3634–3638.

Collapse — human and biological ​

  • Tainter, J. A. (1988). The Collapse of Complex Societies. Cambridge UP.
  • Holling, C. S. (2001). Understanding the complexity of economic, ecological, and social systems. Ecosystems 4(5):390–405.
  • Gunderson, L. H., & Holling, C. S. (eds., 2002). Panarchy. Island Press.
  • Turchin, P. (2003). Historical Dynamics. Princeton UP.
  • Walker, B., et al. (2004). Resilience, adaptability and transformability in social–ecological systems. Ecology and Society 9(2):5.
  • Diamond, J. (2005). Collapse. Viking.
  • Cox-Foster, D. L., et al. (2007). A metagenomic survey of microbes in honey bee colony collapse disorder. Science 318(5848):283–287.
  • McAnany, P. A., & Yoffee, N. (eds., 2009). Questioning Collapse. Cambridge UP.
  • Turchin, P., & Nefedov, S. A. (2009). Secular Cycles. Princeton UP.
  • vanEngelsdorp, D., & Meixner, M. D. (2010). A historical review of managed honey bee populations in Europe and the United States. J. Invertebrate Pathology 103:S80–S95.
  • Sánchez-Bayo, F., & Wyckhuys, K. A. G. (2019). Worldwide decline of the entomofauna. Biological Conservation 232:8–27.
  • Wagner, D. L., et al. (2021). Insect decline in the Anthropocene: Death by a thousand cuts. PNAS 118(2):e2023989118.
  • Cooling, M., et al. (2022). Pathogen-mediated natural and manipulated population collapse in an invasive social insect. PMC 9168452.

These are aggregations / re-circulations of the Forti lab's published work; included for traceability of what triggered the project, not as citable evidence.

Private. Restricted access.