Two studies concerning the specificity of social interactions between mother and infant guinea-pigs were reported. The first study consisted of a series of time-sampling observations of the social behaviour of 2 litters of young guinea-pigs and their mothers housed in a single cage. In a second series of observations, 2 cohabitant litters were separated from their mothers for a few hours each day and their social interactions noted when they were subsequently individually reintroduced to the 2 lactating females. Although the infants suckled significantly more often from their biological mother in each study, and were more often observed to be near or in contact with their mother as opposed to the other female, there were frequent social interactions between infants and the other female (including suckling). When reintroduced to the 2 adult females, the offspring were indiscriminate in their initial approaches towards the latter and likewise showed no preference for mother vs other female in their following responses. The adult females approached their own offspring more often than the other infants when they were initially placed into the cage. No significant differences were found between subsequent approaches towards, or avoidance of, own vs other offspring, however. It was concluded that a reciprocal loose bond of attachment exists between infant and mother guinea-pig - with the mother being able to recognize her offspring at a distance, while the infant apparently requires proximal cues for identification of its mother. An attempt was made to relate the nature of this bond to the highly precocial state in which guinea-pigs are born and their relative independence of maternal care-taking.