The Virginia opossum (Didelphis virginiana), commonly known as the North American opossum, is the only marsupial found north of Mexico. In the United States, the animal is typically referred to simply as a possum. It is a solitary and nocturnal animal about the size of a domestic cat. It is a successful opportunist. It is familiar to many North Americans as they frequently inhabit settled areas due to the associated proximity to food sources, notably trash cans.