[Effects of pup exposure to maternal nest building in virgin female and male mice].

Nest-building behavior in 6 female and 6 male mice of IVCS strain, 20 to 30 weeks old, was studied over a period of 24 days. Weight and style of the nest were used as measures to assess the effects of pup exposure on nest-building. Data were collected between 13 : 00 and 14 : 00 of each day. Female mice with pup exposure showed significant increases in the nest weight and the percentage of good-excellent nest, while males did not respond.