Ants behave like a neural network

Ant colonies never cease to amaze. By their duration life a hundred times higher than that of other insects, by their ability to lift up to 1,000 times their weight, but also by their colonies, surprisingly elaborate! Researchers have looked, in a study published in the journal Proceedings of the National Academy of Scienceson the decision making community that takes place there. “We pioneered an approach to understanding the ant colony as a cognitive-like system, which perceives inputs and then translates them into behavioral outputs.explains Daniel JC Kronauer, first author of the study and head of the Laboratory of Social Evolution and Behavior at Rockefeller University. This is one of the first steps to really understanding how insect societies engage in collective computing.”

Neural network-like behavior

For this, they gradually increased the temperature within ant colonies of different sizes, and observed from which threshold the ants left the nest, and in what way. The individual follow-up was done thanks to a marking of the ants with points of color. And they found that the move of the colony was done suddenly, whereas just before the ants behaved in a usual way. They also found a limit temperature difference depending on the size of the colony.

According to them, everything is decided by a collective evaluation of the cost/benefit ratio, a process similar to the neural calculations from which decisions are made. Thus, for a small colony, moving all the individuals is much less expensive than for a large colony. The move is triggered earlier, so at a lower temperature for a small group than for a large group. But how do ants know the size of their group? According to the researchers, this could be due to the effect of pheromonesthe chemicals that allow them to communicate, which would be more intense for a large colony.