Opossums are the only marsupial in North America. It’s also the only mammal with opposable thumbs, a prehensile tail, and 50 teeth. Thirteen seems to be their lucky number as gestation is 13 days and females have 13 nipples. The bean-sized embryos must make the journey to the pouch and the nipple or they will die. Those finding their way will attach themselves for 2 months before emerging.
They are nocturnal and can climb very well. They do not hibernate but will “hole up” for several days during very cold weather.
Carrion is their primary source of food, but they will also eat insects, frogs, birds, snakes, small mammals, earthworms, berries, and fruits. Essentially, an Opossum is the epitome of an omnivore and will eat anything!
Their live span is quite short with few living more than 2 years; opossums are considered the short-lived animals in the world. They have few predators but human predation is their worst threat with the automobile ranking amongst the major cause of mortality in areas with lots of humans.
You Tube has an interesting mini-documentary on these mammals.
Some good info can be found at Bear Tracker and Wisconsin DNR EEK!