Behavioural interference among eusocial naked mole rats during work

Abstract

It has been reported that individuals of cooperative breeding species occasionally interfere with the work of other group members. However, the occurrence and function of this behaviour are controversial. In the naked mole rat (Heterocephalus glaber), a eusocial mammal, individuals frequently perform ‘tail-tugging’ behaviour, in which an actor holds the tail of another individual with the mouth and pulls that individual to a different place. In this study, we investigated the possible function of this behaviour in the experimental setting of soil excavation. Behavioural observations on three colonies showed that this behaviour was performed and received by individuals of all individual categories (i.e. queen, reproductive males, and workers), although a queen in one colony performed 72.5% of the observed behaviour. Our data support the hypothesis that this behaviour is used to monopolise work in a specific space because (1) tail-tugging was more likely to occur when the actor and recipient were working than when they were not, and (2) the actor performed tail-tugging in a cell in which that individual worked frequently. This study provides a rare example of behavioural interference in a cooperative society and suggests that there is disagreement and conflict regards the opportunity to work among colony members in this eusocial mammal.