Opossums are the only marsupials in North America, meaning that they do not have placentas but develop their young in a pouch like a kangaroo or Tasmanian devil.
Opossums actually have an opposable digit on their hind feet, giving them the ability to handle arboreal life, although many tend to remain on the ground.
Females can give birth to over 50 young between the months of March and August. Most of these will die on their way to finding a teat, or never find a teat due to lack of availability. This ensures that the strong will survive. The final litter size usually ranges from 1 to 15, but usually averages around 10. Gestation is 13 days long and then the young stay in the pouch another 2 months. The eyes open in 58 to 72 days and they are weaned and on their own at approximately 5 months of age. As the opossum gets older (at about 80 days of age), it will come out of the pouch and will be seen clinging to the mother’s side or her back. Baby opossums that are at least 8 to 9 inches long from the nose to the base of the tail are on their own.
Opossum body temperature is 90-99 degrees. They have a lower body temperature than most mammals.
Opossums are very necessary animals to our environment. They are scavengers and help keep the earth clean. They feed on carrion, or road kill, invertebrates such as bugs, fruits, and small vertebrates.
Opossums are nocturnal (active at night) and have a solitary life. They are usually non-
aggressive and prefer to “play possum” or fake death. When frightened, hey hiss with their mouths gaping open and excrete foul-smelling feces and a thick green gel-like substance. But remember, just because a species is characteristically non-aggressive, some individuals can be aggressive and will attack. Care should always be taken when working with wild animals.
If you have found an opossum that is in need, please refer to our Wildlife Help and Resource page: https://vetmed.illinois.edu/wildlife/wildlife-help-and-resources/opossum/