Aggregation behaviour as a source of collective decision in a group of cockroach-like robots

Abstract. In group-living animals, aggregation favours interactions and information exchanges between individuals, and thus allows the emer-gence of complex collective behaviors. In previous works, a model of a self-enhanced aggregation was deduced from experiments with the cock-roach Blattella germanica. In the present work, this model was imple-mented in micro-robots Alice and successfully reproduced the agrega-tion dynamics observed in a group of cockroaches. We showed that this aggregation process, based on a small set of simple behavioral rules of interaction, can be used by the group of robots to select collectively an aggregation site among two identical or different shelters. Moreover, we showed that the aggregation mechanism allows the robots as a group to “estimate ” the size of each shelter during the collective decision-making process, a capacity which is not explicitly coded at the individual level.