MOTHER RATS INTERACT DIFFERENTLY WITH MALE AND FEMALE OFFSPRING

60 lactating Long-Evans rats were observed to interact differently with male and female pups during the 1st 18 days postpartum. Differences were related to the gender composition of the home litter (GHL), to the sex of a single introduced pup, and to the sex of individual pups within the litter. Major differences were the greater time spent in licking the anogenital region of own male pups and the greater stimulation of anogenital licking by male foster pups, an effect that did not interact with GHL or age of pup. GHL interacted with day of testing to affect nest building and time spent near pups. (31 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1979 American Psychological Association.