The opossum or possum is a very interesting mammal, and very common in Virginia, although originally from South America. Many things make them interesting, one of which is the game of "playing dead". It turns out that this is completely involuntary, like a person fainting. Triggered by something scary, a few things happen. In their incapacitated state, lips go back; showing teeth, they may foam at the mouth, their eyes close and a gland puts out a nasty odor which acts as the most convincing part of the play dead trick. All to convince any potential attacker that they're not worth eating.
For the gardener, they can be beneficial, eating bugs, mice, slugs, and other small rodents (like voles). Of late they've been touted as a great tick annihilator, killing them by just cleaning themselves or feeding on them in the wild. With their incredible immune system, they don't get Lyme disease, in fact they are immune to the venom of rattlesnakes (and a few other poisonous snakes). Only one in eight hundred will be affected by the rabies virus if bitten by a rabid animal.
Their life span is short, two to four years and the female will have two litters per year. The males travel from winter to summer, looking for a mate. Those hit by cars this time of year are mostly males.
As the only marsupial in North America, the gestation period for the young is only two weeks. The tiny babies are born and travel to the mother's pouch (not all make it), where they will live for two to three months. A female will become very burdened by her young, often hanging as a weight in the pouch beneath her, she can support up to thirteen babies. As she travels for food, it can be slow going, a bad time as many are hit by cars on nights in late spring and early summer.
At the height of spring at the plant farm (many years ago) a mother possum was hit on Route 50 and her young had traveled to our greenhouses. Fortunately a wildlife rehabilitator was there shopping, and they were gathered and boxed to go home with her. We ended up with nine babies.
There is actually a Opossum Society of the United States where you can find answers to lots of questions and misconceptions. I learned that they don't eat chickens and they're one of the harder animals to raise because of dietary needs. Call a wildlife rehabilitator if you find babies. And the "playing dead" trick may last up to four hours, watch for twitching ears prior to their waking up.