Opossums are North America’s only native marsupials. They frequently spark questions about their potential danger to humans and pets. Despite common misconceptions, opossums are generally non-aggressive and often misunderstood, rarely posing a direct threat to people or domesticated animals.
Understanding Their Behavior
Opossums are shy, nocturnal animals that prefer to avoid confrontation. Their primary defense mechanism is an involuntary response known as “playing ‘possum” (tonic immobility). During this state, the opossum feigns death, becoming still with an open mouth, drooling, and sometimes emitting a foul odor. This involuntary behavior deters predators who prefer live prey. While they may hiss or bare their many teeth to appear intimidating, actual bites are rare, occurring only if an opossum feels cornered or severely threatened.
Health Risks and Disease
Concerns regarding opossums often revolve around their potential to carry diseases. Any mammal can contract rabies, but opossums are remarkably resistant to the virus.
Their naturally lower body temperature (94-97°F) makes it difficult for the rabies virus to survive and replicate. Rabies cases in opossums are extremely uncommon, accounting for less than one percent of reported wildlife cases.
However, opossums can carry other pathogens, though human transmission risk is generally low. They may carry bacteria like Leptospirosis (spread through urine) and Salmonella (transmitted through feces). Contact with contaminated water, soil, or surfaces can lead to infection, with symptoms from flu-like illness to more severe complications.
Opossums can also host parasites like fleas, ticks, and mites, which can transmit diseases like Lyme disease. Despite carrying parasites, opossums are meticulous groomers and consume many ticks, potentially reducing tick populations. Horses can be affected by Equine Protozoal Myeloencephalitis (EPM), a neurological disease linked to a parasite shed in opossum feces.
Potential Nuisance Factors
Beyond health concerns, opossums can become a nuisance due to their opportunistic foraging habits. They are scavengers attracted to food sources like unsecured trash, outdoor pet food, or compost piles. Opossums may also seek shelter in human structures like porches, sheds, attics, or crawl spaces, especially during colder months. While not inherently destructive, their presence can sometimes lead to minor property disturbances or damage to insulation.
Safe Coexistence Strategies
Coexisting with opossums involves simple prevention. Secure outdoor trash cans with tight-fitting lids and bring pet food indoors at night to eliminate common attractants. Block access points to crawl spaces, decks, and sheds with hardware cloth or by sealing gaps to prevent denning. Regularly remove fallen fruit and clear brush piles to reduce food sources and hiding spots.
If an opossum is encountered, leave it alone and allow it to move on naturally. For sick or injured animals, contact local animal control or a wildlife professional. Opossums contribute positively to the environment by consuming ticks, garden pests, and scavenging carrion, acting as nature’s clean-up crew.