We have a coop and run that are completely enclosed with an electric fence. We have never lost any chickens or ducks to a predator. A couple day ago my daughter found once of our roosters dead on the coop floor, missing a head. That night we put our 4 ducks, 3 hens and 1 rooster in the garage and put a camera in the coop. We got footage of a HUGE possum climbing the roosts. Last night we set a trap and this morning relocated the possum miles away. We can't figure out how It got in since out coop and run is surrounded by an electric fence. It's very concerning because now I don't feel like my ducks and chickens are safe. Any ideas?