Facilitation of maternal transport by Norway rat pups.

Abstract

Norway rat young assume a characteristic posture as they are being transported to a new nest. This transport response is normally elicited by the tactile stimulation received from the mother''s teeth on the dorsal and lateral skin. The pup transport response develops gradually over the first 10 days of life and can then be reliably elicited until the 3rd wk after which the response becomes more difficult to stimulate. The response is seen during the time that mothers carry relatively large pups which may be unwieldy. Although the elimination of the pup transport response does not impede the transport behavior of the mother when pups are small, its elimination interferes with the mother''s locomotion and increases the time to transport young when pups have become relatively large.