The opossum is a good climber, having five toes on each foot including thumbs and big toes which are opposable and allow grasping of branches. Opossums have 50 teeth - more than any other mammal in North America. Since they are marsupials, opossums have pouches in which the young spend most of their time during development. Opossums are solitary, only living in groups when a mother is raising her young. Opossums are generally nocturnal, but may venture out during the day in winter.
Opossums are opportunistic feeders, eating what is available.
Foods include insects, slugs, berries and other fruit, frogs, small mammals, carrion, pet food, and scraps from household garbage cans. Oregon's opossums are restricted to the west side of the state where the environment is most suitable. Opossums prefer to live in forests where their dens can be in close proximity to a water source such as a stream or pond. Opossum dens are commonly made from abandoned burrows of other animals, in hollow trees, brush or rock piles, or under buildings. When threatened, the opossum will fall on its side and remain almost completely still, drool, and emit a foul smelling odor from its anal glands.