ABSTRACT
From infancy to adult life, huddling is a major component in the behavioral repertoire of Norway rats. During infancy, rats are severely limited in their sensorimotor capabilities, yet they are capable of aggregating and displaying forms of group regulatory behavior. We show that huddling as aggregative behavior can emerge as a self-organizing process from autonomous individuals following simple sensorimotor rules. In our model, two sets of sensorimotor parameters characterize the topotaxic responses and the dynamics of contact among infant rats. The first set of parameters are conditional probabilities of activity and inactivity given prior activity or inactivity and the second set are attractions for objects in the infant rat’s environment. Using computer simulation, we have found that the behavior of the model and of actual rat pups compare very favorably. In particular, synchronized bouts of inactivity in aggregations 434of 10-day old rats emerge by spreading deactivation. We discuss the model and the underlying approach, developmental emergence of social interactions, and how group thermotaxis and individual geotaxis may facilitate aggregation and cohesion.
