Prairie State Wildlife receives numerous calls regarding opossums each year. The opossum or the animal better known as the Virginia opossum is found throughout the mid western and eastern United States. The opossum is found throughout Illinois.
Opossums are cat sized animals and are gray and white in color. They have long pointed snouts with a pink nose. The ears and tail are hairless and the tail is often described as ratlike. Opossums are North America's only known marsupial and the mammal with the most teeth (50). Opossums can be quite large with an adult male specimen documented as large as 15 pounds. Most commonly males are larger than females with males averaging approximately 8 pounds and females 4 pounds.
Opossums are found in diverse habitats within Illinois, ranging from heavy forest, interspersed woodland surrounded by row crops, to open fields. Because they adapt to so many differing habitats they are often found in close proximity to man. Opossums find living in urban and suburban areas in Illinois very suitable and often den under sheds, stoops and cement patios. Often times opossums will utilize abandoned burrows excavated by other animals. Most calls to our office are for opossums denning under sheds, decks and stoops or the occasional lost opossum in a garage. They will den in attics if they have easy access to the roof of a residence and an entry hole which has already been made by another animal, usually a raccoon. Opossums rarely tear or rip into buildings.
Opossums are well known for feeding on carrion (dead animals) but feed on many other food stuffs. They feed on grass, vegetable matter, garbage, earthworms, insects and invertebrates. Opossums prefer to eat the maggots found on dead animal flesh, are known to be cannibalistic and will commonly feed on poisonous snakes. Opossums, over thousand of years of adaptation, are resistant to the venom of all North American poisonous snakes. Opossums find both dog and cat food very appealing and we often receive calls regarding opossums observed eating these foods.
Opossums are not territorial, usually are solitary and often wander for long periods. Because of this, the home range for opossums is difficult to determine. They are primarily nocturnal (active at night) but may be seen during the day in winter (during warm spells). If opossums are attacked, they may feign death and the opossum falls on its side and does not move. When the threat abates the animal recovers and continues on.
Opossums are North America's only marsupial and the breeding season runs from January to November. Generally two litters a year are produced. Gestation is approximately 13 days and after the young are born they find their way to the pouch. The young are blind and helpless and attach to a nipple inside the pouch. The number of nipples available is variable but is normally 13. As many as 21 young may be born but the number that survive depends on the number of nipples available. If the young do not attach to a nipple they will perish. The average litter size is seven but could be much higher. The young remain attached to the nipples approximately 60 days and remain in the pouch 7 to 8 weeks. The young remain with the mother 6 to 7 weeks until they are weaned.
Damage is often limited to nuisance burrowing, raiding bird feeders, raiding garbage cans and feeding on dog food. One very difficult problem is denning opossums under front stoops. In winter opossums often succumb to the harsh conditions and customers discover in early spring they have a rotting carcass of an opossum under the front stoop.
Trapping is the recommended control method for this species.