The Virginia Opossum is a cat-sized, tree-climbing animal with a pale face, naked leaf-like ears, and pink, pointy nose. Their underfur is pale in color with a coarse, grizzled overcoat that makes the animal appear gray to brown to black. On the ground they move about with a slow, hobbling gait. The opossum is unlike any other animal in the United States: it has 50 teeth, a pouch in which it carries its young, a prehensile tail and opposable thumbs on its hind feet. Although they can be aggressive when threatened, when facing a larger opponent they often "play dead," entering into a state of catatonia in hopes they will be passed over. Their flexible tail is scaly and mostly hairless, and used for balance and gripping branches and objects making them agile climbers. They do not sleep hanging from their tails. The Virginia opossum has the distinction of being North America's only marsupial, sometimes considered a "pouched" mammal. This is an ancient species is more closely related to the koala and the kangaroo than it is to the rodents in the area. Opossums are mainly active during the night. During the day they sleep in opportunistic dens and nests of other animals or spaces under human structures. In New England, they may make more permanent nests during the winter to return to each day. Virginia opossum are opportunistic scavengers. Their diets include many kinds of bugs and insects, carrion, snails, mice and rats, and fallen fruit. They are useful in their environments as they will eat food other animals might not.