Ants recognize enemies through experience

A study by researchers at the University of Freiburg, Germany, has revealed that ants use associative learning to recognize enemies. The experiment demonstrated that ants remember odors from aggressive rival colonies and adjust their behavior based on these memories. Learning improves colony defense by allowing ants to attack intruders from previously known colonies.

Main results

Ants can distinguish members of their own colony from those of rival colonies by specific odors. The study introduced negative experiences for groups of ants with rivals from different colonies.

Ants that encountered aggressive opponents exhibited greater aggression in later interactions with members of the same rival colony.

On the other hand, those who interacted with passive opponents showed less aggression.

The experiments were carried out in two phases.

In the first, groups of ants were exposed to daily one-minute encounters with members of rival colonies, which were classified as either aggressive or passive.

In the second phase, these groups were put in contact with rivals from known or unknown colonies.

Ants exposed to aggressive opponents showed higher aggression than those that interacted with passive rivals.

Learning mechanism

The aggression suffered by the ants acts as an unconditioned stimulus, while the odor of the rival colony serves as a conditioned stimulus.

This association leads to the development of an "enemy template", which is stored in the ant's memory.

Additional experiments confirmed that ants not only distinguish, but adjust their aggressive behavior depending on previous experience.

More information can be found at doi.org/10.1016/j.cub.2024.11.054