Rat Pups Prefer their Siblings to their Mothers: Possible Implications for the Development of Kin Recognition

Abstract

Previous experiments have indicated that for rat pups some learning of their kin's characteristics is required for kin recognition. By differentially scenting the mother and litter with artificial odours, the possible role of each in the development of this ability can be assessed. 12- and 20-day-old rat pups were given a preference tests between the odour associated with their mother and an odour associated with their littermates. It was hypothesized that, because of the importance of the mother to her pups, individuals would preferentially acquire information from her and thus exhibit a preference for that odour. The results, however, did not support this: Both 12- and 20-day-old rat pups were found to prefer their littermate's odour to that of their mother. A further experiment revealed this did not reflect an aversion to their mother's odour. This preference for sibling littermates probably reflects the greater exposure of littermates to one another. The possible advantages of learning about one's kin from littermates are discussed.