Intromission pattern and species vaginal code in relation to induction of pseudopregnancy.

Mechanical stimulation was used to mimic normal vaginal stimuli during copulation in the mouse; the number and rate of intromissions were crucial influences on reproductive success. The best combinations for the mechanical induction of pseudopregnancy were comparable to those male behaviors normally seen during mating. The behavior of the male coincides with a species-related vaginal code, increasing chances for reproductive success between cospecifics.