Most wild animals keep their distance from people — and you should keep your distance from wildlife. Wild animals can be unpredictable. While actual attacks are unlikely, they most often occur when animals are startled, sick or habituated to people, or if they feel threatened.
If an animal appears sick, it will likely die soon. It is often best to leave it alone. If there has been no contact with humans or pets and the animal is not threatening or aggressive, no further action is needed. Because there may be other infected animals in the area, stay on guard.
If a wild animal is in your yard behaving aggressively and there has been no contact with people or pets, contact your local animal control or state wildlife agency immediately. They will assess the threat and take appropriate action to deal with the offending animal.
If you have been attacked, bitten or scratched by a wild animal that was behaving aggressively, immediately clean the area with soap and water for several minutes then see your doctor as soon as possible (ideally within 24 hours) and consult your local health department. Even if no obvious injuries are sustained, but you have had direct contact with an aggressive wild animal, you should consult your doctor for advice and treatment and local health department to assess disease exposure risk.
If your pet has had direct contact with a wild animal that was behaving aggressively (i.e., it was bitten or scratched), call your veterinarian for advice. If the aggressive animal was potentially rabid, it is best not to touch your pet during this time since the rabies virus from the saliva of the infected animal may be present on the hair and skin. If you must handle your pet, protect yourself by wearing gloves and protective clothing. If you have handled your pet without protection, consult your doctor and local health department for advice.
Although any warm-blooded mammal can contract rabies, opossums rarely get the disease. Aggressive behavior by an opossum is usually in response to a situation where they feel threatened. They may hiss, screech, or bare their teeth to ward off an attack. If that doesn’t work , they may feign death,, an involuntary response commonly referred to as “playing possum”.