Some people are afraid of possums because they do have claws and sharp teeth. But the possums see a human as a potential predator, another animal to be feared. They may respond with hissing, standing up on their rear legs (to increase their apparent size) and showing their teeth. These are all the same sort of defensive behaviours that you may see from many animals but they do not mean the possum is ready to attack. It actually wants you to back away and give it a chance to escape.
An injury from any wild animal is a human health risk because of potentially dangerous bacteria on their teeth and claws, so any bite or scratch from a possum must be thoroughly cleaned and, if deep, treated by a doctor to ensure infection is controlled.
While possums have adapted to the built environment, competition for suitable spaces to hide and sleep, often leads to fighting and the stress from a high density of animals reduces their immunity systems. In Brisbane the result has been an increase in the incidence of necrotic dermatitis, a serious skin infection caused by a mix of bacteria including Staphlococcus aureus. For the possum, it can result in the loss of large patches of skin usually around injuries from fighting but the infection often spreads to the eyes causing blindness and death from starvation. For humans, this type of infection does pose a risk since Staph aureus is the same type of infectious bacteria that has evolved into “Golden Staph” in our hospitals.
Since possums do not attack and put on a threat display only so they can escape, why would humans get bitten? Possums should not be hand fed as they will move very fast to grab items with their claws and your fingers can easily get in the way! Injured possums may be handled to take them to a vet but most human to possum interactions are a result of poorly managed attempts to feed wild possums. If you have ever tried to feed tame kangaroos at a wildlife park you will remember how they try to grab the bags of pellet food with their claws, not realising how easy it is to injure our hands. When an easy supply of food is provided to any wild animal, it changes the animals behaviour as it comes to depend on that food source; it fails to forage for other types of food and may then become demanding and possibly aggressive if there is not enough food supplied when it feels hungry.
There are Brisbane homes where possums and even brush turkeys have entered open doors and even pushed through cat and dog flaps, to try to find the food that had become a regular part of their diet. They then became scared and trapped inside the house and a confrontation with humans was unavoidable.
So the best advice is not to feed wildlife but if it is something you really want to do, ensure the food is in the garden, not near the house. You should only provide food occasionally so it is only a small part of the wild animal’s diet. If you are confronted by a possum in your home, back away and remember the animal is very frightened and only trying to escape. If there is now way to get it safely outside call Peter Possum to get it released outside.