Ant communication (and how to take advantage of it)

The mission

You have been tasked by the secret shadow government to retrieve a special microchip that holds all the information needed to replicate the original Doritos taco flavor. If this chip were to fall into the wrong hands, it may cause the collapse of society as we know it. Luckily, you are a highly skilled agent and this is not the first world-ending threat you dealt with. The only problem, however, is that this computer chip is safeguarded by a highly deadly ant species. These ants are extremely territorial and capable of swarming a person and reducing them to nothing in less than a second. They are also somehow resistant to all known weapons and toxins. To retrieve this chip, you will need to be shrunk down to the size of an ant, infiltrate the nest without provoking them, and leave with most of your limbs intact. The shrinking technology has already been developed, all you need to do is figure out how to effectively disguise yourself, lest you meet your end by a horde of mandibles and stingers. Luckily, we have the information you will need to complete this task and save the world. 

Ant communication 

You know that ants are social creatures, and with any social creature, communication is key. Us humans have evolved to communicate mainly using sound and sight, but ants have opted for a different form of speech. They communicate by secreting chemical signals known as pheromones. Legendary myrmecologists E.O. Wilson and Bert Hölldobler summarized this system best: each pheromone is a ‘word’ and the combination of different ones is a ‘phrase’. These phrases can range from “Food over here!” to “Kill this guy!”. When workers pick up on these phrases through specialized organs on their antennae, they act accordingly. If there is a nice food source nearby, they will follow the pheromone trail left behind by the worker who found it. Similarly, if they recognize you as an enemy, they will send a signal that will spread through the colony and to mobilize an attack. To effectively disguise yourself as an ant, you have to learn and utilize their hidden language.

Pheromones are easy for us to synthesize in a laboratory. We do not expect this to be a significant obstacle. What we will have difficulty synthesizing is the unique scent that every colony has. Ants can recognize nestmates by touching their antennae to different parts of their bodies and smelling them. Nestmates will all carry the same scent while intruders will smell different. In order to gain access to the colony, we will need a small sample of an ant to replicate their unique smell.

When pheromones can not get the job done, ants rely on sound. As part of our research, we have picked up many ants and held them to our ears. In their state of panic, the ants emitted tiny squeaking noises. These noises are caused by the rubbing of a specialized organ on ant gasters, known as the stridulatory organ. This sound alerts nestmates that there is danger nearby or that they need help. The leaf-cutting ant, Atta caphaloes, has mastered this technique. Because they commonly live in tropical, rainy environments, their nests are prone to cave-ins. Cave-ins often result in many workers being buried alive. The buried workers emit a high-pitch sound that travels through the ground as vibrations and alert their nestmates to their location. The nestmates rush to the source of the sound and dig up their buried sisters. This may be difficult for you to replicate. We recommend you listen to this sound sample on repeat for several hours in order to prepare yourself.

How to take advantage of it

Now that we know the basics about how ants communicate with each other, we can figure out how to infiltrate their ranks. Still, this mission will not be easy, so we will have to consult some experts. These organisms regularly hijack ant communication networks and twist them for their own benefit. 

“Why would anything willingly interact with murderous insects?” I hear your inquisitive mind ask. 

Ants have a multitude of resources. They gather large amounts of food and can even sometimes grow their own. Even the ants themselves can be a delicious treat to those that dare to try. It is a dangerous game though. These expert ant mimics have taken thousands upon thousands of years to perfect their disguises. We do not have that time, but we can learn from them.

Jumping spiders

Ants are amazing at communication using chemicals and sound, but their sight is severely lacking. Many ants have adapted to life in dark cavernous nests where eyesight is not needed. This weakness is something that many species of jumping spiders have learned to take advantage of. These spiders will mimic the form and behavior of an ant so it can hang around workers as they forage outside of the nest. They will raise their front two legs and twitch them to mimic antennae. They move around erratically like a foraging ant would typically do. They will even change their hunting behavior to be more “ant-like”. Instead of pouncing on their prey like normal jumping spiders will do, they will instead run toward them. When these spiders are not around ants, they drop their act and display more typical spider behavior. This mimicry seems to be enough to trick ants because they often show no sign of aggression toward these spiders.

While this may be a good time for the spider to have a quick snack, the primary reason they do this is to gain the ants protection. Ants are dangerous in the insect world, and many species are inherently aware of that. If an insect were to accidentally trigger the aggression of just one worker, they can easily be swarmed by dozens in a matter of minutes. These jumping spiders are acutely aware of this and choose to exploit this fear to protect themselves from predators. This mimicry is not enough to gain access into the killer ant nest, but it can get as close to a hunting party. The ant suit is already in development.

Alcon blue butterfly

To gain access into the nest, we will need to take notes from the Alcon blue butterfly (Phengaris alcon). This species has smartly recognized that an ant nest is one of the safest places on Earth to raise children. It purposefully lays its eggs near plants that ants will forage from. In the first few stages of its development, it will feed exclusively from that plant. For the last few stages, it relies solely on its ant hosts. These butterfly larvae have learned how to mimic both the appearance and smell of an ant larva. For its first step to infiltrating the colony, it acts like an ant larva that has escaped the nest. Once an ant stumbles upon it, the larva collects its smell (and therefore the scent of its nestmates) and incorporates it into its arsenal.

Inside the nest, the ants feed and take care of the butterfly as if it was one of their own. However, just being fed is not enough. This butterfly has more nasty tricks up its wings. It mimics sounds produced by the ant queen to raise its social status within the colony. These sounds ensure that if the nest is attacked, the workers will prioritize its safety over that of the actual ant larvae. After a few months, the now adult butterfly will emerge and safely leave the nest so that it can repeat this cycle with its own eventual young. We have already gone way over budget with the ant suit so we cannot make a larva suit as well. You will have to make due with what we have.

Slave-making ants

We have already figured out how to approach the colony and gain access without being torn apart. However, we just got intel that the microchip will set off an alarm, alerting all of the killer ants to your presence as soon as you pick it up. For you to get out of there alive, we will need an escape plan. Fortunately, we have one last trick up our sleeves. 

No species is as good at tricking ants than the ants themselves. While most ants construct their colonies with their own workers, some ants have decided that it is easier to steal workers instead. These ants are known as slave-maker ants. The queens of these slave-makers raise specialized workers that are adept at infiltrating ant colonies and stealing their worker larvae. The stolen larvae are raised to adulthood in the colony and tasked with performing all domestic duties in the nest. A direct assault on an ant nest with only a small group of workers is suicide. To aid their attack, slave-maker ants use history’s most potent weapon: chemical warfare. When these ants raid a colony, they release pheromones that trigger an alarm response in enemy workers. This causes the workers to panic and become unable to mobilize a force to fight back. Through the panic, the raiding ants kill the adult workers, steal their larvae, and flee back to their colony. Once the larvae emerge in their new nest, they accept the nest as their own and start working. They will defend their ‘nestmates’, assist in raids, and may even battle against their former nestmates.

End mission

Now that we have learned from the experts, we are ready to start the mission. We have a perfectly constructed ant suit that smells exactly like the killer ant colony and can release pheromones that trigger an alarm response. Please review your ant sounds and ant behavior before embarking on this vitally important task. Godspeed, friend.

Bibliography

Hölldobler, B., & Wilson, E. O. (1998). Journey to the ants: a story of scientific exploration. Harvard University Press.

Hölldobler, B. (1978). Ethological aspects of chemical communication in ants. In Advances in the Study of Behavior (Vol. 8, pp. 75-115). Academic Press.

Markl, H. (1965). Stridulation in leaf-cutting ants. Science, 149(3690), 1392-1393.

Cushing, P. E. (1997). Myrmecomorphy and Myrmecophily in Spiders: A Review. The Florida Entomologist, 80(2), 165–193. https://doi.org/10.2307/3495552

Cushing, Paula E., Spider-Ant Associations: An Updated Review of Myrmecomorphy, Myrmecophily, and Myrmecophagy in Spiders, Psyche: A Journal of Entomology, 2012, 151989, 23 pages, 2012. https://doi.org/10.1155/2012/151989

Hayes, M.P. The biology and ecology of the large blue butterfly Phengaris (Maculinea) arion: a review. J Insect Conserv 19, 1037–1051 (2015). https://doi.org/10.1007/s10841-015-9820-3

Regnier, F. E.; Wilson, E. O. . (1971). Chemical Communication and “Propaganda” in Slave-Maker Ants. Science, 172(3980), 267–269. doi:10.1126/science.172.3980.267

Czechowski, W., Godzińska, E.J. Enslaved ants: not as helpless as they were thought to be. Insect. Soc. 62, 9–22 (2015). https://doi.org/10.1007/s00040-014-0377-z