Antchitecture: The Building of Harvester Ant Nests

From the surface, harvester ant nests are simply unremarkable. As I explored the field station across the street from HMC where we conduct our research, I often walked right past one without noticing a thing. Their presence is signaled only by a small hole descending into the Earth, and sometimes a mound of dirt with seed husks scattered around it. I’ve often wondered how these humble abodes successfully protect the harvester ant queens and larvae from predators, store half a pound of seeds, and house the thousands of worker ants it takes to keep the colony running. The answer lies underground, where a dense network of tunnels and chambers form the evolving metropolis that harvester ant colonies require. 

The unremarkable nest entrance of a harvester ant colony. [1]

    Harvester ant nests are truly impressive structures. They can stretch to more than 7 meters deep and often last the decade-long lifespan of their queen. A few major tunnels descend like a helix with chambers and tunnels shooting off the side, forming spiral staircase-like passageways that the ants can travel to get from one place to another. Excavating all of that dirt from the ground is a lot of work, and it takes hundreds of harvester ants working around 4 to 7 days to dig enough tunnels and chambers for the nest to be livable.

Aluminum casting of a nest created by the Florida harvester ant Pogonomyrmex badius, with Walter R. Tschinkel standing next to it for scale. [2]

    Harvester ants take special care to keep their nests organized. While digging up Florida harvester ant nests, Florida State University professor Walter R. Tschinkel discovered that the queen and larvae usually stay in the deepest parts of the nest. Worker ants are distributed across the middle and top of the nest, with workers that take care of the larvae and transport resources residing towards the middle and workers that forage for seeds living near the top. Interestingly, as individual worker ants age, they move up the nest and take on social responsibilities based on where they live. First, they take care of larvae, then they transport resources around the nest, and finally they forage for seeds.

    The top of harvester ant nests are especially interesting because they are so complex. Because the ants need a lot of seeds to survive the winter, most of the nest’s volume is at the top where the foraging ants can easily fill it with seeds. The chambers at the top are more interconnected than anywhere else in the colony, and it turns out these connections are really important for the foraging ants. With so many connections, it is easy for ants to find one another and communicate the location of a new food source, allowing them to recruit as many workers as possible to gather the seeds.

    It turns out that harvester ants may even have some lessons for us in how they build their nests. Research by University of Bristol PhD student Luke Leckie on Lasius niger ants revealed that the ants restructure their nests in response to diseases like fungi. By strategically plugging tunnels, they cordoned off an area for infected ants and created isolation zones for vulnerable colonymates like the queen and larvae. As the Bee Lab continues to study how California harvester ants respond to the threat of invasive ant species, maybe we will uncover nest architecture tricks that keep the harvester ants safe.

    So next time you see a small, boring ant nest, think about all of the complicated structure lying underneath your feet!

Further Reading

Bottinelli, A., van Wilgenburg, E., Sumpter, D. J., & Latty, T. (2015). Local cost minimization in ant transport networks: From small-scale data to large-scale trade-offs. Journal of The Royal Society Interface, 12(112), 20150780. https://doi.org/10.1098/rsif.2015.0780 

Giuroiu, A. (2024, August 6). Ants: How cities influence them and inspire urban planning. Architecture Lab. https://www.architecturelab.net/how-ants-could-influence-urban-planning/ 

Leckie, L., Andon, M. S., Bruce, K., & Stroeymeyt, N. (2025). Architectural immunity: Ants alter their nest networks to prevent epidemics. Science, 390(6770), 266–271. https://doi.org/10.1126/science.ads5930 

Milius, S. (2016, February 5). Harvester ants are restless, enigmatic architects. Science News. https://www.sciencenews.org/article/harvester-ants-are-restless-enigmatic-architects 

Pinter-Wollman, N. (2015). Nest architecture shapes the collective behaviour of Harvester Ants. Biology Letters, 11(10). https://doi.org/10.1098/rsbl.2015.0695 

Tschinkel, W. R. (1999). Sociometry and sociogenesis of colony-level attributes of the Florida Harvester Ant (hymenoptera: Formicidae). Annals of the Entomological Society of America, 92(1), 80–89. https://doi.org/10.1093/aesa/92.1.80 

Tschinkel, W. R. (2004). The nest architecture of the Florida Harvester Ant, Pogonomyrmex Badius. Journal of Insect Science, 4(1). https://doi.org/10.1093/jis/4.1.21 

Tschinkel, W. R., & Hanley, N. (2017). Vertical Organization of the division of labor within nests of the Florida Harvester Ant, Pogonomyrmex Badius. PLOS ONE, 12(11). https://doi.org/10.1371/journal.pone.0188630

Media Credits

[1] Photo uploaded to Wikimedia by W0lfie.

[2] Photo taken by Charles F. Badland.