The Virginia opossum, commonly known as the North American opossum, is the only marsupial found in North America north of Mexico. In the United States, it is typically referred to simply as a possum. A solitary and nocturnal animal about the size of a domestic cat, and thus the largest opossum, it is a successful opportunist. It is familiar to many North Americans as it is often seen near towns, rummaging through garbage cans, or lying by the road, a victim of traffic.
The Virginia opossum is the original animal named "opossum". The word comes from Algonquian wapathemwa meaning "white animal". Colloquially, the Virginia opossum is frequently called simply "possum".
Virginia opossums can vary considerably in size, with larger specimens found to the north of the opossum's range and smaller specimens in the tropics.
The Virginia opossum is noted for reacting to threats by feigning death. This is the genesis of the term "playing possum", which means pretending to be dead or injured with intent to deceive. In the case of the opossum, the reaction seems to be involuntary, and to be triggered by extreme fear. It should not be taken as an indication of docility, for under serious threat, an opossum will respond ferociously, hissing, screeching, and showing its teeth, but with enough stimulation, the opossum will enter a near coma, which can last up to four hours. It lies on its side, mouth and eyes open, tongue hanging out, emitting a green fluid from its anus whose putrid odor repels predators. Besides discouraging animals that eat live prey, playing possum also convinces some large animals that the opossum is no threat to their young.
Opossums are omnivorous and eat a wide range of plants and animals such as fruits, insects, snakes, and other small animals. The Virginia opossum has been found to be very resistant to snake venom. Persimmons are one of the opossum's favorite foods during the autumn. Opossums in captivity are known to engage in cannibalism, though this is probably uncommon in the wild. Placing an injured opossum in a confined space with its healthy counterparts is inadvisable.
The Virginia opossum does not hibernate, although it may remain sheltered during cold spells.
Opossums, like most marsupials, have unusually short lifespans for their size and metabolic rate. The Virginia opossum has a maximal lifespan in the wild of only about two years. Even in captivity, opossums live only about four years.
