Opossums have an impressive defense mechanism of seizing up and flopping to the ground when they experience fear. They emit a smelly secretion from their anus to deter predators and can appear dead for hours. However, the opossum has no control over this reaction. The comatose-like state is an involuntary reaction triggered by stress.

Compared to other mammals, opossums have unusually short lifespans for their size and metabolic rate and live only 2-4 years.

Although they are generally solitary animals, a group of opossums is known as a passel.

The Virginia opossum was once widely hunted and consumed in the United States and was often served with sweet potatoes, especially in America's southern region.

Opossums got their name from the word "aposoum," a term that means "white beast" in the language of the Algonquin, a Native American tribe in the northeast United States.

Even though the opossum of North America is often referred to as a "possum", a possum is a different animal. Possums live in Australia, New Guinea, Sulawesi, New Zealand and China. They are brown in color and are more closely related to kangaroos.

The muscles in an opossums tail are not strong enough to support an adult's weight for more than a moment. Although young opossums are sometimes spotted dangling temporarily by their tails, even juveniles don't sleep while hanging upside down. However, the prehensile tail can curl tightly around branches, grasp and carry objects, and help stabilize the opossum as it clambers around in trees and bushes.

An opossum's tail makes up 1/3 of its body length.

Although they are different animals, the possums of Australia and the North American opossums share some similarities. Both are marsupials, they have tails that can grab branches and most are approximately the size of a domestic cat.

Like many marsupials, male opossums have bifurcated genitalia. When European colonizers first landed in North America, they didn't know what to make of this. One explanation they came up with was that male opossums impregnated females through the nose and when it was time to give birth, the mother opossum blew her young out of her nostrils and into her pouch.