Sex and the worker—parasite relationship between rats

Abstract

When rats are paired in a modified Skinner box with a water dipper and a bar attached to opposite walls, a worker—parasite relationship develops. One of the rats performs most of the bar-pressing whereas the partner receives the reward almost without working. The influence of sex on this social interaction was studied through testing 14 pairs composed of a male and a female rat. The proportion of workers and parasites was the same for male and females. The role of sex in competitive situations between rats is discussed.