Opossum Biology:Opossums are North America's only marsupial or pouched mammal. Just like the koala and kangaroo, Possums (as their name is more often pronounced) carry their newborns around in a pouch by their belly. These animals have been dated back to the time of the dinosaur, leaving them with the nickname “The living fossil”.Females have litters up to twice a year (the father always skips town!). Babies, typically 5 to 8 in a litter are ready to leave mommy's
pouch and walk around out on their own by 4 months of age. That's when they are 7 to 9 inches, nose to rump, and weigh about 10 to 16 ounces.
Opossums have a prehensile tail. Prehensile means that the tail is adapted for seizing, grasping, and wrapping itself around objects. The common picture of opossums hanging by their tails is, for the most part, a myth. A young opossum may hang briefly by its tail. But an adult opossum's body is far too heavy to be held suspended by its tail. The opossum actually uses its tail to stabilize its body while climbing.