Possums are generally harmless to human beings and household pets as long as they're not cornered or threatened. Possums often play dead when frightened, but they are more likely to puff up, snarl and hiss when confronted. They are a threat to poultry and often kill birds or steal eggs.
Most possums will go out of their way to avoid humans. When they feel that they are in a dangerous situation, they will try to get away, slowly and quietly. Possums are nocturnal and prefer to feed on rodents, reptiles and insects and usually hide during the day. People can discourage possums from visiting homes by securing pet food and making sure that poultry coops are fortified against predators.