Individual versus collective associative learning in ants

Although associative learning has been traditionally studied at the individual level, it may also operate in group contexts, particularly in social species such as ants. This study investigated whether colonies of Temnothorax rugatulus ants exhibit collective learning-defined as group-level information acquisition emerging from dynamic individual learning-by examining whether individuals learn more effectively in a colony than alone. Using a visual associative learning paradigm, we trained ants to associate a visual cue with food availability and compared performance between isolated individuals and colonies. We tested subjects across 17 sessions, comprising acquisition and reversal phases, and quantified performance based on the time spent at correct versus incorrect cues. Our results revealed that ants trained in colonies learnt associations more rapidly than those trained alone during both phases. Additionally, observations showed that colony-trained ants spent more time in correct corridors during training and engaged in more tandem runs early in learning. These findings suggest that social interactions-particularly recruitment behaviour-enhance associative learning of individual ants in colonies. This study underscores the importance of considering the social environment in learning research and suggests that collective learning may be an adaptive mechanism in social animals. This article is part of the theme issue 'The evolution of collective intelligence'.