A possum is a marsupial mammal found in numerous areas of the world, including North America, Australia, New Zealand and China. They are often found in suburban locales, being pesky intruders to outdoor garbage cans, gardens and food placed outdoors for pets. While it may seem as though these animals are abnormally large when you encounter them in the dark of the night, a possum's actual size may not be quite as large as it seems.
According to The Opposum Pages website, possums generally grow to about 15 to 20 inches long, which is about the size of a standard house cat. They weigh about 10 to 13 lbs. on average. However, depending on the individual possum's diet and level of activity, he may be bigger in terms of weight. The more well-fed a possum it is, the bigger he will be in terms of girth and the bigger he may seem overall.
In part, a possum's size is attributed his very indiscriminate eating habits. Possums eat just about anything, including table scraps, pet food, leaves, berries, insects and even small snakes, in some instances. Possums follow the food trail, going wherever good is readily available. Therefore, possums with a plentiful food supply--such as those that live close to a well-stocked trash can--may get bigger than those that live deeper in the wild.
Possums may growl, hiss or show off their very sharp teeth if they feel threatened; in fact, sometimes, a possum may seem larger than he is if he has a fairly large girth and shows you those teeth. However, in reality, possums refer to shy away from confrontation and are docile creatures. In fact, the common term "playing possum," comes from the Virginia opossum's tendency to play dead when threatened.
No matter what the size, a possum has a fairly short life span. According to Opossum.org, these mammals only live two to four years. Common predators of the possum population include humans (particularly in cars), bobcats, foxes, coyote, cats, dogs and owls. Most other animals, states The Opossum Pages site, simply ignore the possum, regardless of its size.