A further investigation of the development of mouse-killing in rats

Rats in the group receiving both food deprivation and competitive experience killed significantly more mice than rats in the other groups, suggesting competitive experience is an important factor in the development of the mouse-killing response in rats.

Abstract

Several previous investigations have suggested that competitive experience is an important factor in the development of the mouse-killing response in rats. However, the question of whether the competition involved or food deprivation associated with the competition is the critical factor has been raised. In the present study three groups of rats were used. In one group (N = 40) rats were food deprived and were placed daily, in pairs, in a situation where they could compete for food. A second group (N = 20) was food deprived but not exposed to the competitive situation, while a third group (N = 20) was not food deprived. Animals were tested daily for 15 consecutive days for the development of the killing response. Rats in the group receiving both food deprivation and competitive experience killed significantly more mice than rats in the other groups.