We experience the world around us through five major senses: vision, touch, hearing, smell, and taste. For us, those five senses aren’t quite equal… you could use vision or touch to navigate through your house, but it would probably be quite difficult to get to your kitchen only using your sense of smell. Yet, most ants do just that: they primarily rely on a sense of “smell” to communicate with other ants and navigate the world around them.
Ants don’t smell quite like we do. We both smell volatile organic compounds (VOCs), lightweight chemicals that easily disperse in the air at room temperature. While we use our nose to detect these chemicals, ants use two antennae attached to their head. The antennae have many specialized cells, each of which can interact with a specific VOC. When they are stimulated by their respective VOC, the cells send a signal to the ant’s brain letting it know that a specific chemical is present.
Scanning electron microscope image of the head and antennae of the ant Protanilla lini. [1]
One of the coolest ways ants use their sense of smell is to identify each other. Ant bodies are usually coated in waxy chemicals called cuticular hydrocarbons (CHCs), but the exact composition of these chemicals varies between different ant colonies and species. So, ants can catch any ants from other colonies trying to sneak into their nest by smelling their CHCs. But this system isn’t foolproof. Insects like rove beetles groom ants to steal their CHCs and then live among their colonies as parasites. Other ants have CHCs so similar between different colonies that they can’t distinguish between each other. But they can use that to their advantage, like the invasive Argentine ant Linepithema humile which has thousands of colonies cooperating with each other to form a formidable “supercolony”.
Ants also rely on their sense of smell to find food sources, home, and any other place they need to go. As ants leave the colony to search for food, they use specialized glands in their abdomen to leave behind homing pheromones like breadcrumbs they can follow home. If they find food, they deposit foraging trail pheromones on their way back. Then, other ants find the foraging trail pheromones and follow it to get food. But just like breadcrumbs, these pheromones don’t last long because they evaporate or get concealed by other chemicals. How, then, do ants communicate reliably in diverse and changing environments? One way they make their pheromone signals more detectable is by combining multiple chemicals together, like in the trail pheromone of the Argentine ant or alarm pheromone of the clonal raider ant Ooceraea biroi. They also deposit fewer pheromones when they are unsure and stronger pheromones to correct mistakes. By carefully controlling the chemicals they deposit as they walk, ants have developed an entire language to reliably communicate with each other.
Next time you find yourself stumbling through your home in the dark, try using your sense of smell. You’ll gain a new appreciation for those ants that won’t stay out of your kitchen.
Further Reading
Choe, D.-H., Villafuerte, D. B., & Tsutsui, N. D. (2012). Trail Pheromone of the Argentine Ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae). PLoS ONE, 7(9), e45016. https://doi.org/10.1371/journal.pone.0045016
Czaczkes, T. J., & Heinze, J. (2015). Ants adjust their pheromone deposition to a changing environment and their probability of making errors. Proceedings of the Royal Society B: Biological Sciences, 282(1810), 20150679. https://doi.org/10.1098/rspb.2015.0679
Dajose, L. (2026, February 9). Beetles Go Stealth Mode to Infiltrate Ant Societies. California Institute of Technology. https://www.caltech.edu/about/news/beetles-go-stealth-mode-to-infiltrate-ant-societies
Lopes, L. E., Frank, E. T., Kárpáti, Z., Schmitt, T., & Kronauer, D. J. C. (2023). The Alarm Pheromone and Alarm Response of the Clonal Raider Ant. Journal of Chemical Ecology, 49(1–2), 1–10. https://doi.org/10.1007/s10886-023-01407-4
Vásquez, G. M., Schal, C., & Silverman, J. (2009). Colony fusion in Argentine ants is guided by worker and queen cuticular hydrocarbon profile similarity. Journal of Chemical Ecology, 35(8), 922–932. https://doi.org/10.1007/s10886-009-9656-y
Voigt, K., & Menzel, F. (2022, September 5). Conflict of interest resolved: Wax on the body surface of ants can simultaneously optimize two essential requirements. EurekAlert! https://www.eurekalert.org/news-releases/963783
Volatile organic compound. (2026). In Wikipedia. https://en.wikipedia.org/w/index.php?title=Volatile_organic_compound&oldid=1340400415
Wyatt, T. (2017, February 6). How Animals Communicate Via Pheromones. American Scientist. https://www.americanscientist.org/article/how-animals-communicate-via-pheromones
Media Credits
[1] Richter, A., Garcia, F. H., Keller, R. A., Billen, J., Katzke, J., Boudinot, B. E., Economo, E. P., & Beutel, R. G. (2021). The head anatomy of Protanilla lini (Hymenoptera: Formicidae: Leptanillinae), with a hypothesis of their mandibular movement. Myrmecological News, 31. https://www.biotaxa.org/mn/article/view/68159
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