Olfactory mediation of mother–young contact in Long-Evans rats

21-day-old Long-Evans pups, unlike 16-day-old pups of the Wistar strain, (a) found the odors emitted by adult virgin females of their strain attractive, (b) found the odor of anal excreta of adult virgin females of their strain attractive, (c) found anal excreta of virgin female rats as attractive as those of lactating rats of their strain, and (d) were less attracted by the odor of anal excreta of a lactating rat than by the odor of the lactating rat itself. Results indicate that descriptions in the literature of olfactory communication between Wistar rat dams and their young cannot be generalized to rats of other strains or ages. (9 ref)