Virginia opossum (Didelphis virginiana), 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. 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 it is often seen near towns, rummaging
through garbage cans, or as roadkill.
Over 70 million years ago dinosaurs roamed the Earth. While
they are now extinct, one animal who shared the same land with the
dinosaurs still exists today
Despite its appearance, the opossum is not related to the rat.
In fact, the opossum is a marsupial, or pouched mammal,
and is therefore related to other marsupials such as the kangaroo
and the koala. Like kangaroos and koalas, infant opossums stay inside
the mothers pouch to nurse and develop. The opossum holds
the distinction of being North Americass only marsupial.
Opossums are born after an 11-13 day gestation period. The pink,
embryonic-looking infants are so small at birth that 20 could fit
into a teaspoon. The infants continue to develop inside the pouch.
As they grow and the pouch becomes full, the juveniles then ride
on the mothers back until they are old enough to go out on
The opossum has an average lifespan of 1 to 2 years. This short
lifespan is due in part to the presence of many predators including
dogs, cats and people. Sometimes the opossum is able to escape death
by playing possum or feigning death, and in so
doing the predator may lose interest in the apparently dead animal
and not eat itThe name opossum is derived from an Algonquian
Indian word apasum, meaning white animal. While there
are over 65 species of opossums, only one, the Didelphis virginiana,
more commonly known as the Virginia opossum, is native to North
America. Didelphismeans double womb and refers to the pouch as a
secondary place of development for the infant opossums. Virginiana
refers to the state of Virginia where the opossum was first observed
by early English colonists. However, opossums today can be found
throughout most of the United States and portions of Canada and
The opossum has many interesting features. It has 50 teeth,
more than any North American land mammal. Its hairless tail is prehensile
and is used for grasping branches, balancing and carrying nesting
material. The opossum does not hang upside down by the tail, a common
misconception. The opossum also has opposable thumbs on its hind
feet for holding onto branches.
opossums hanging from their tails. Image taken by Frank Lukasseck/Corbis.
Whether rural, residential or in the wilderness, opossums are
a benefit to any area they inhabit. Their diet includes all types
of bugs and insects including cockroaches, crickets and beetles.
They love snails. They also eat mice and rats. The nocturnal opossum
is attracted to our neighborhoods by the availability of water,
pet food left out at night and overripe, rotting fruit that has
fallen from trees. The opossum in turn helps keep our neighborhoods
clean and free of unwanted, harmful garden pests and rodents, which
may carry diseases. The opossum has earned the title of Natures
Little Sanitation Engineer.