The Virginia opossum, Didelphis virginiana, is North America’s only native marsupial, recognizable by its pale fur, pointed snout, and prehensile tail. This nocturnal animal has successfully adapted to human environments, frequently being sighted in suburban yards and neighborhoods. Their presence often sparks misunderstandings and fear due to their unique appearance and defensive displays. Clarifying the actual risks of physical harm and disease transmission helps homeowners coexist peacefully and implement effective management practices.
Possum Behavior and Threat of Injury
Opossums are non-aggressive animals that prefer to avoid confrontation with humans and pets. They possess 50 sharp teeth, which they display in a wide-open mouth when threatened. This gaping display, accompanied by hissing and drooling, is an effective bluff meant to deter a predator. Opossums typically only resort to biting if they are cornered, trapped, or actively handled, making human bites extremely rare.
When subjected to extreme fear, their most famous defense mechanism is an involuntary state known as tonic immobility. This catatonic state, often called “playing possum,” causes the animal to fall limp, slow its heart rate, and reduce its breathing rate. During this reflex, the opossum may also release a foul-smelling fluid to enhance the illusion of being dead. This response can last from a few minutes to several hours until the danger has passed.
Disease Risks Associated with Possums
Rabies is extremely uncommon in opossums due to a specific physiological trait. The rabies virus struggles to survive and replicate in the opossum’s naturally lower body temperature, which is typically under 95 degrees Fahrenheit. While they are not immune, documented cases of rabid opossums are rare compared to other common carriers like raccoons, skunks, and bats.
Bacterial and Parasitic Risks
Opossums can be carriers for a number of other bacterial and parasitic diseases, primarily transmitted through their urine and feces. Leptospirosis is a bacterial disease that can be transmitted if human skin or mucous membranes come into contact with water or soil contaminated by infected opossum urine. Symptoms can range from flu-like illness to severe kidney or liver complications.
Other parasitic infections like Coccidiosis and Toxoplasmosis are spread via the ingestion or contact with feces containing the microscopic parasites. Toxoplasmosis is a particular concern for pregnant women and immunocompromised individuals. Opossums can also carry external parasites, such as fleas and ticks, which can indirectly transmit diseases like Murine Typhus or Tularemia to humans or pets.
Opossums and Tick Control
Opossums play a beneficial role in controlling the population of disease-carrying ticks. They are meticulous groomers and efficiently consume and destroy over 90% of the ticks that attempt to feed on them. This high rate of tick destruction means that a single opossum can eliminate thousands of ticks in a season, significantly reducing the number of ticks available to transmit illnesses like Lyme disease.
Safe Handling and Deterrence Methods
The most effective strategy for managing opossums is modifying the environment around the home to make it less appealing. Since they are attracted by accessible food and shelter, removing these resources is the primary method of deterrence. All outdoor food sources, including pet food bowls, bird feeders, and fallen fruit, should be secured or removed before nightfall when opossums are most active.
Securing trash cans with locking lids or heavy-duty bungee cords prevents access to garbage. Exclusion techniques involve sealing all potential entry points into structures like sheds, garages, and crawl spaces using materials such as quarter-inch wire mesh. Inspecting foundation gaps and under decks is important, as opossums can enter through surprisingly small openings.
If an opossum is encountered, maintain a safe distance and allow the animal to move away on its own. Never attempt to handle or capture an opossum, even if it appears to be in the tonic immobility state. If a sick, injured, or trapped opossum is found inside a structure, contact local animal control or a professional wildlife removal service.
Motion-activated lights and sprinklers can also serve as a deterrent, as the sudden stimulus startles the nocturnal animals. Scent-based repellents, such as ammonia-soaked rags or predator urine products, can be placed near den sites, but they often require frequent reapplication.