Newborn opossums arrive in their mother's pouch by crawling there on their own. Though tiny and blind, newborn opossums instinctively climb upward towards their mother's pouch where they will each fasten to a teat and remain there for about 3 months. A full-grown opossum is about the size of a house cat. The adult opossum frequently uses its tail to assist in climbing. Opossums eat practically anything.
Most opossums live in underground dens.
They will sometimes use hollows of trees when dens are unavailable and have been known even to take over an abandoned squirrel's nest. Opossums are meticulously clean animals. They bathe and groom themselves frequently, much like cats, and have been observed to stop and clean themselves several times during a single meal. Many opossums in colder areas suffer frostbite on their tails and ears which are not protected by fur. They also forage for food during daylight hours rather than at night as they do in summer.