How do ants communicate?
How does an ant society actually function? The ants are unable to talk to each other, and their eyes are nowhere near our human eyes. So how do they communicate with each other?
When presented with the word communication, most humans would probably associate it with language or speech. Something spoken, created by the use of our tongue and mouth to shape and articulate. This way, we can create an infinite amount of words and as a result tell extremely complex stories. The communication of ants is not quite as advanced, but most people would probably agree that it is impressingly refined.
An ant colony can consist of several millions of workers. How can such a large society be the well-organised machinery we’ve observed it to be? The ants solve the barriers of communication in several ways:
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Scent (pheromones)
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Touch
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Body language
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Sound
The ant antennas are the keys to the mystery of their communication. With the help of an advanced system of pheromones they can “smell” a wide range of topics, ranging from colony activity to territorial conquest. Through millions of years the ants have developed specific pheromone-cocktails to communicate different things to fellow ants. To receive the messages they use their antennas, much the same way we would use our nose if blind and deaf.
Of course, all scents aren’t known by man, but we do know a lot about their system. For example, each colony carries their own unique set of pheromones, making it possible to tell friend from foe. For a human being it might seem odd that an ant can sort this out in a matter of milliseconds, but through scent it is possible, and it often comes in very handy. (1)
A major and a minor worker of the species Atta sexden. Maybe the smaller ant is trying to communicate with the larger one cutting through a leaf. Photo: Alex Wild.
How ants communicate through motion and touch
Myrmecologists Bert Hölldobler and Edward O. Wilson gives an account of observations of weaver ant communication (Oecophylla longinoda) in their book Journey to the Ants. It is clear that it is all actually quite advanced. For example, the ants tend to lay out scent trails to food sources, like breadcrumbs, for other workers to find and follow. When a single worker has found something she will run back to the colony whilst sprinkling small drops of pheromones on the ground for other workers to follow. The myrmecologists explains that there are five different ways the ants can mix and vary these signals. When a worker ant meets a member of the colony, she can tell it things by moving her body in a specific manner, or simply by the touching of antennas. The other ant is then provided with a relatively clear image of what it should look for at the end of the trail. If the first ant has found something edible, she will most likely give the other ant a taste of it from a sample out of her mouth. (2)
Ants communicate through body language
Just as humans, the ants use body language to communicate things. They can tell the other ants things by lightly touching or stroking the receiver in different ways. This way, they can combine signals of pheromones with that of touch and body language, providing an advanced form of communication. One example of a peculiar dialogue is when the ants, by lightly pressing a section of another ant’s head, can produce a jaw reflex, giving the first ant the opportunity to taste the diet of the other ant. It is not uncommon for ants to save some of their food for later or for members of the colony. This dialogue might seem strange to us, but there is no reluctance involved in this from any of the two ants.
Do ants speak to each other? Yes!
Another peculiar way of how ants communicate is by sound. A majority of ant species use it to communicate, although it is commonly unknown to most people because of its low resonance. The ants can procure different sounds by scraping their legs on a washboard-like part of their body, thus accomplishing different sounds. Although we may not hear it, other ants can. The sound is actually possible for us to perceive if we hold an ant very close to the ear, listening carefully.
The sounds are used in different ways, depending on the species. A great example of the use of sound is when a worker ant has been trapped somewhere. Maybe through the collapse of a tunnel or chamber – blocking all the exits. The ant can use sound as a distress call, signaling their location to the other workers through the walls. This could not be achieved by pheromones.
12 different categories of communication
Myrmecologists have mapped out twelve different categories of how ants communicate.
- Alert/Warn
- Entice
- Recruit (to food sources or new nest locations)
- Grooming (the cleaning and tending to other ants)
- Trophallaxis (the exchange of liquids, orally/anally)
- Exchange of solid food
- Peer pressure
- Recognition (members of the colony, determine caste, telling apart dead or living ants)
- Influencing castes (stimulating or preventing the development of different castes)
- Controlling rivals (other fertile females of the same nest)
- Marking territories (distance to the colony, marking of territorial borders)
- Sexual communication (determining species and genders as well as synchronising the nuptial flight)
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References
1. Per Douwes, Johan Abenius, Björn Cederberg, Urban Wahlstedt (2012) Nationalnyckeln “Steklar: Myror-getingar. Hymenoptera: Formicidae-Vespidae” p. 26 (Swedish)
2. Bert Holldobler & Edward O. Wilson (1995) “Journey to the ants” p. 46
3. Bert Holldobler & Edward O. Wilson (1990) “The Ants” p. 227
