Development of olfactory control of feeding-site selection in rat pups.

The results of the present experiments provide two lines of evidence consistent with the view that development of olfactory control of feeding-site selection in rats depends on experiences during ontogeny. First, normally reared pups ate at a feeding site at which either an anesthetized conspecific or conspecific excreta were present in preference to a clean site, whereas pups reared without contact with conspecifics were not influenced in their choice of feeding site by these social stimuli. Pups allowed contact with conspecifics for only the 5 days immediately prior to testing exhibited, like normally reared pups, a strong preference for feeding sites marked with social stimuli. Second, exposure of pups to an arbitrarily selected odor rendered that odor subsequently capable of influencing feeding-site selection. Comparison of the results of the present experiments with those of similar studies, in which a different measure of pup olfactory preference was used, revealed that the factors affecting development of olfactory preference vary as a function of test situation.