Norway rats help social partners in need in response to ultrasonic begging signals

Abstract

Begging signals are widespread in animals and have been extensively studied in the context of brood care. In contrast, the functionality of begging signals expressed among adults has not yet been scrutinised experimentally. Norway rats (Rattus norvegicus) have been shown to express 50-kHz calls towards a social partner when in need of help to obtain food. Here, we tested with help of playbacks whether focal subjects exposed to a high rate of ultrasonic calls would increase their helping rate towards their social partner. The propensity to help a partner was significantly enhanced when the focal rats were exposed to playback with a doubled number of calls relative to baseline conditions. To the best of our knowledge, this provides the first evidence of increased help in response to an experimentally altered begging signal in adult animals.