There are two litters per year. If the first litter is lost, the female will immediately return to estrus and breed again. The young are extremely altricial, and remain attached to a nipple for 50-65 days. Weaning occurs at 95-105 days. Females reach maturity at 5.5-7 mo, but probably do not breed in their first year.
Females usually have two years of reproductive activity.
Populations are usually composed mostly of young of the year. May share the burrow systems or nests of other small to medium-sized mammals. Important predators include owls and dogs. Motor traffic and severe winter conditions are important sources of mortality. Ecology of the opossum on a natural area in northeastern Kansas.