Use of foraging trails by Norway rats

Six experiments were undertaken to explore the effects of residual trails deposited by one Norway rat,Rattus norvegicus, on subsequent choice of path by conspecifics. A rat moving away from (but not towards) a feeding site deposited a trail that biased path choice by its fellows. The relative attractiveness of a trail was affected by the number of times it had been traversed by a rat on its way to and from food, but not by the amount of food a rat ate before depositing a trail. There was no evidence that trails contained information that would allow a rat to move directly towards food rather than directly away from it. Possible sources of the trails deposited by Norway rats as they leave feeding sites are discussed. 1996 The Association for the Study of Animal Behaviour