Opossums are 13 to 20 inches long and weigh 5 to14 lbs. Their short, leathery black ears are almost hidden in fur behind their intense black eyes. Their long, whiskered snout, long hairless tail and black, gray or brown coat mixed with white gives them the appearance of a large rat. Their front paws are heavily padded with five thick, stubby toes and short nails. The five toes on their rear paws include a shorter, nailess, opposable toe that allows them to grasp and hold branches. The long hairless tail can also wrap around branches and used for carrying nesting material.
Opossums are found in dark, cool places near water. They prefer deciduous forests but are highly adaptable and live in and around marshes and swamps, near farmlands, on prairies and in urban areas. Their nests of grass and leaves are found in hollow logs, rock piles, garages, under buildings and in attics. They will also nest in burrows abandoned by other other animals. Although they may maintain several nests in an area of 30 to 90 acres they do not defend their territory and may share it with other opossums.
Opossums are not picky eaters. They eat live and dead plants and animals and are classified as omnivores.They are opportunists and eat almost anything including dog food, frogs, snakes, maggots, earthworms, smaller animals and rotting fruit. Because they feed at night they depend on a keen sense of smell to locate food and are often hit by vehicles while eating animals that have been killed on the road.
Opossums have an 11- to 13-day gestation period. They can have three litters each year with as few as 8 or as many as 20 young per litter. At birth they are blind, furless and are about the size and color of a white bean. They immediately crawl through the birth canal and into the pouch where they latch onto a teat and begin to suckle and grow. At about two months they are too large for the pouch and clamber on their mother's back for another month. While on her back they learn to avoid predators and how to find food. They are weaned at about five months and breed after one year. Predators and vehicles limit the opossum's lifespan in the wild to about two years.