Possums can and do kill poultry. I keep my coop locked up at night. My neighbor used to raise chickens and pheasants. He had all sorts of trouble with killer possums. They climb right up on to the roosts at night and take them. Some particularly greedy ones learn that the combs are the best and eat only that and move on to the next. Yes, they are scavengers, but they are also opportunists. And a sleeping chicken on a roost is a pretty easy opportunity. DH shot one in the hay barn last night. We caught it eating the cat food. Possums also carry a disease that is deadly to horses. If they poop in the hay and a horse eats it, the horse can contract a devastating disease called epm. So to all of you people that like to trap and relocate, please think of the people that will be inheriting your problem.