Risk aversion as a survival strategy in ants
Ants are excellent navigators and always find their way back to the nest. But how do they react when an obstacle or a predator blocks their path? An international team including Antoine Wystrach, a CNRS researcher at the Research Centre on Animal Cognition (CNRS/Université Toulouse III - Paul Sabatier), has shown that ants are capable of changing their familiar route to avoid traps thanks to an aversive learning mechanism: by associating visual cues with negative experiences, they can memorize potentially dangerous routes. This was discovered when scientists "trapped" desert ants1 by placing a pit trap with slippery walls in their path; a small bridge hidden by twigs was their only exit. On the first attempt, all ants rushed - at almost 1 m/s - towards the nest and fell into the hole. However, on the second attempt, they had already adapted their behaviour: as they approached the trap, some ants stopped to scan their environment before making a quick detour and co...