Opossum, or Possum, the common name for a family of American marsupials. (A marsupial is a mammal whose young are born so soon after breeding that they need to be protected from the outside world. They mature attached to the mother's nipples in an external pouch, or some other specialized area such as a skinfold, on her abdomen.) Opossums are distantly related to Australian marsupials such as kangaroos and phalangers (often called Australian opossums). Although two species are found in North America, most opossums live in Central and South America.

Opossum babiesOpossum babies often ride on their mother's back.
Which Marsupial Lives in North America?

Only one kind of marsupial lives in the wild in North America. That’s the common opossum (uh PAHS uhm), also called the Virginia opossum. Millions of years ago, this opossum traveled north from South America.

The tail is very important to the opossum! Its long, scaly tail acts as a fifth hand. The opossum wraps its tail around a tree branch and uses its free hands to grab nearby branches. Its tail is called a prehensile tail. The tail has adapted for grasping and holding on.

Opossums range in length from 3 to 20 inches (7.5 to 50 cm). The animal has along, pointed nose; round, hairless ears; short legs, and a chunky body. Many species have a thumblike big toe on each hind foot and a prehensile (grasping) tail, which are used in tree climbing. Opossums are able to hang from trees by their tails for brief periods.

Like other primitive mammals, they have small brains and many teeth (about 50).

How Many Hands Does an Opossum Have?

All four of an opossum’s feet work like hands. A young opossum can even hang by its tail and use all four “hands” at once. How do opossums do this? Well, you can use your thumb to touch any of your other fingers, right? Imagine if you could do the same thing with your big toe. An opossum can. On its hind foot, an opossum has an inside toe that bends like a thumb. It can touch any other toe.

Having feet that work like hands is especially helpful for climbing trees. An opossum can tightly grip branches while climbing to the treetops.

Older, heavier opossums cannot hang upside down. They would fall right out of the tree.

Opossums are forest animals that live singly in tree nests or in dens on the ground. They are active at night, and they do not hibernate in winter. Most opossums eat any kind of food, but especially plants, insects, eggs, small animals, and carrion (decaying flesh). Opossums sometimes raid crops and refuse heaps. In some areas they are hunted for sport, for food, and for their fur.

The Northern, or Virginia, opossum is found from southern Canada to Costa Rica. Its body is from 13 to 20 inches (33 to 50 cm) long; its tail, 10 to 21 inches (25 to 53 cm). Largest of the opossums, these animals weigh 5 to 14 pounds (2.3 to 6.4 kg). Their soft coats consist of black, brown, gray, or off-white underfur and long, white or black guard hairs (the outer fur). They are noted for their tendency to feign death, or "play possum," when cornered, a strategy that causes most predators to leave them unmolested. The Central American opossum is found from Mexico to northern Argentina.

At birth–12 to 13 days after mating—the young of North American opossums resemble tiny worms. Each one crawls to its mother's pouch and attaches itself to one of the 13 teats there. After two months, the young are ready to leave the pouch for increasing lengths of time. They follow their mother on her food-gathering trips, occasionally riding on her back. After another month, the young are independent.

How Big Is a Baby Opossum?

A baby opossum is less than a 1/2 inch (13 millimeters) long. That’s tinier than a honey bee. A whole litter of opossums can fit in the palm of your hand. A female opossum can give birth to as many as 20 babies at one time. (A kangaroo usually has only 1 baby at a time.)

A female opossum has her first litter in early spring. Before she gives birth, she builds a warm, cozy den. The opossum moves into a burrow abandoned by an animal or into a hollow tree. She fills the den with many layers of leaves and twigs.

The female uses her tail to carry the leaves back to the den. First, she gathers the leaves with her teeth. Then she uses her front legs to pass the leaves to her hind legs. Using her hind legs, she tucks the leaves into a loop that she has made with her tail.

Opossum or Possum—Is There a Difference?

James Cook, an English explorer, first visited Australia in 1770. This explorer saw a furry little animal that lived in trees. It had a gripping tail and a pouch on its belly.

This furry creature reminded the explorer of the American animal called the opossum. So he gave the same name to the Australian animal. But these two marsupials were not closely related. The name “opossum” was shortened to “possum” (PAHS uhm) to tell it apart from the American animal. Possums, not to be mistaken for opossums, are marsupials that live in Australia and nearby islands.

The brush-tailed possum from Australia is about the size of a cat. It has a beautiful coat that comes in silver-gray, black, or reddish-brown. It can live in many places, but it likes the forest best because there it can rest in tree hollows.

What Does It Mean to “Play ‘Possum”?

Have you ever kept very still and pretended to be asleep when you really weren’t? You were “playing ’possum.” The opossum uses this trick, too.

When an opossum faces an enemy, it pretends to be dead. The opossum closes its eyes, or it stares without blinking. Its tongue may even hang out of its mouth. The opossum will remain motionless even if an enemy tosses it about.

The opossum can lie perfectly still for up to six hours. Most animals won’t try to eat another animal if they think it’s dead. When the enemy goes away, the opossum rolls over, gets up, and walks away.

Do Possums or Opossums Make Good Pets?

Just a few kinds of both animals can be good pets. The sugar glider is one kind of possum that can be a pet. It is easily tamed. The sugar glider got its name because it has a sweet tooth. It likes the sweet nectar of flowers.

One kind of opossum that makes a good pet is the short-tailed opossum. It looks like a cute mouse. It is usually found in South America. Short-tailed opossums have short, thick fur. They help get rid of pests around the house because they love to eat insects and baby mice.

Most other kinds of possums and opossums are not so friendly to people. They prefer to live on their own. They nest in trees or bush areas. They eat fruit, flower blossoms, and insects.

The Northern opossum is Didelphis virginiana; the Central American, D. marsupialis. Both are of the family didelphidae.