According to Schubert, opossums have been around about 70 million years, since the age of the dinosaurs. They are the only marsupial in North America, and they do not chew, dig, or carry rabies. They have very short life spans: one to two years in the wild and three to four in captivity. Schubert said people are frightened when they find opossums, but the best course of action is to leave them alone.