You’ve heard of hive mind, but what about colony mind?
According to a new study out of Rockefeller University, the way that ant colonies make group decisions closely mimics the way neurons behave in the human brain. In other words, they follow a colony mind.
Scientists observed this trait in action when studying how ants react to rising temperatures within their dirt burrows. As the nest grows hotter, each ant feels the sting of heat beneath its feet, but they all will march along dutifully—until a certain point, when they all suddenly scurry out together, abandoning the nest as one.
That behavior—”almost as if the colony of ants has a greater, collective mind”—does, in fact, reflect how networks of neurons operate, the Rockefeller research posits. Put simply, ants combine sensory information with a crude analysis of how much effort a decision involves, before making that decision. This parallels the neural computations firing within our own brains when we make decisions—down to the cost-benefit analysis. (For example: If you’re only a little bit hungry, but very tired, you may not be motivated to leave your home to forage for food—but when you grow hungry enough, the effort becomes worth it.)
For the ants, the sensory information is the temperature of the nest. But the amount of effort required, the research suggests, is where the group dynamic comes in—a swarm of hundreds of ants vacating a nest takes much more effort than just one ant fleeing. When researchers experimented with colonies of 36 worker ants, the group collectively exited the nest once the temperature hit roughly 34 degrees Celsius. But with a colony of 200 worker ants, they stayed put until the temperature soared past 36 degrees Celsius.
The size of effort may also trace back to pheromones—chemical particles secreted by insects and animals that allow them to communicate biologically with one another—which researchers suspect form the mechanism by which ant colonies can rush out in perfect coordination.
But at a macro level, the whole event can be boiled down to the human-brain-like process of “sensory response thresholding.”
“We pioneered an approach to understand the ant colony as a cognitive-like system that perceives inputs and then translates them into behavioral outputs,” Daniel Kronauer, head of Rockefeller’s Laboratory of Social Evolution and Behavior and a co-author of the study, said in a statement. “This is one of the first steps toward really understanding how insect societies engage in collective computation.”