Do They Know What They Are Doing? Cognitive Aspects of Rescue Behaviour Directed by Workers of the Red Wood Ant Formica polyctena to Nestmate Victims Entrapped in Artificial Snares

Abstract

Ant rescue behaviour belongs to the most interesting subcategories of prosocial and altruistic behaviour encountered in the animal world. Several studies suggested that ants are able to identify what exactly restrains the movements of another individual and to direct their rescue behaviour precisely to that object. To shed more light on the question how precise is the identifi-cation of the source of restraint of another ant, we investigated rescue behaviour of workers of the red wood ant Formica polyctena using a new version of an artificial snare bioassay in which a nestmate victim was bearing on its body two wire loops, one placed on the petiole and acting as a snare, and an additional one on the leg. The tested ants did not direct preferentially their rescue behaviour to the snare. Moreover, the overall strategy adopted by the most active rescuers was not limited to precisely targeted rescue attempts directed to the snare, but consisted of attempts to find a solution to the victim’s problem through frequent trial-and-error switching between various subcategories of rescue behaviour. These findings highlight the importance of precise identifica-tion of cognitive processes and overall behavioural strategies for better understanding of causal factors underlying animal helping behaviour.