SOCIAL INTERACTION AS A POPULATION-REGULATING MECHANISM IN MICE

Abstract

Male laboratory mice were isolated for 3 weeks after weaning before being placed in groups of 1, 2, 4, 8, 16, and 32 animals. The groups were placed into cages of increasing size; so space per mouse remained constant. Indicator organs were weighed to determine the effect of the increasing number of social interactions. Weights of spleen and adrenal glands showed that hypertrophy increased as the number of possible social interactions increased. Testes development was inhibited by an increased number of possible social interactions. Populations may be regulated by increasing the number of social contacts without decreasing the space per animal.