.

Abstract

The infant is, at birht, very dependent on maternal behavior and its survival is very difficult in the absence of either the mother or a conspecific adult which could care for it. In order to analyse maternal behavior of mice, 12 females and their litters were observed from the birth of infants to the 25th dau postpartum. In relation to mothers, it has been noted that 1) Both mother-infant contact and nest building time decrease during the first week; 2) Maternal grooming of infant also decreases after the 14th day; 3) Locomotion and self-grooming (head, paws, ventral and dorsal regions) were very irregular and not showing significant alterations during the the lactation period. As far as the infants are concerned, it has been observed that 1) Locomotion and self-grooming start at the 7th day and increase with age; 2) Nest material manipulation and social-grooming (the infants groom or are groomed by other infants) start approximately at the 11th day of age; 3) Ingestive behavior (eating and drinking) - wich reveals physical independence from the mother - begins around the 16th day postpartum and coincides with increased locomotor activity. It has been concluded that mother-infant interactions in mice are very dynamic and the maintenance of this link depends on the behavior of both mother and infant alike.