Ants learn from past encounters and display more aggression against familiar aggressive opponents and less aggressiveness against passive opponents, suggesting that ants can adjust their behavior based on experience.A team of evolutionary biologists from the University of Freiburg has shown that ants are able to learn from experience. The study was co-led by Dr. Volker Nehring, associate researcher in the Evolutionary Biology and Animal Ecology group, and PhD student Mélanie Bey.
In the study, ants were repeatedly exposed to competitors from different nests. The ants remember these interactions and adjust their behavior accordingly. Their aggression increases when they encounter ants from nests that have been previously associated with aggression.
In contrast, ants that had only encountered passive individuals from another nest showed less aggressive behavior. These findings highlight the ability of ants to adjust their responses based on past experience. The research was published in the journal Current Biology.
Ants are more aggressive towards neighbors
Ants use scent to distinguish members of their own nest from those of other nests. Each nest has its own specific scent. Previous research has shown that ants are particularly aggressive toward close neighbors.
They are particularly prone to opening their jaws to bite, or spraying acid to kill rivals. They are less likely to take such aggressive actions against nests that are further away from their own. Until now, it wasn't clear why this happened.
Nehring's team has now discovered that ants remember the smell of their attackers. This is why they are more aggressive when faced with competitors from familiar nests.
More aggressive toward competitors from familiar nests
The scientists conducted the experiment in two stages. In the first phase, the ants received different experiences: one group encountered ants from their own nest, a second group encountered aggressive ants from competitor nest A, and a third group encountered aggressive ants from competitor nest B.
In a subsequent testing phase, the researchers examined the performance of different groups of ants when encountering competitors from Nest A. Ants that had already encountered ants of the same species from the nest during the first phase showed significantly more aggression than the other two groups.
To test the extent to which ants from specific nests showed increased aggression, the scientists repeated the experiment in a slightly modified form. In the first phase, they differentiated between aggressive and passive ants. They severed an ant's antennae to ensure its behavior was passive. During the second phase of the experiment, ants that had previously encountered only passive competitors became significantly less aggressive.
"We often think of insects as functioning like pre-programmed robots," Nehring said. "Our study provides new evidence that ants also learn from experience and can hold grudges." Next, Nehring and his team will investigate whether and to what extent ants adapt their olfactory receptors to their experiences, reflecting what they also learn at this level. "
Compiled from /scitechdaily