Opossums are very aggressive when threatened. They will hiss and show their teeth to predators and apparently, just like skunks, they also shoot a nasty liquid from their behinds to keep them away. They will play dead as well and will not move until the predator is gone. The Opossum are very good climbers and will usually build a nest in a tree or they will enter another animal's hole in the ground. They never actually dig their own holes either. Some of their predators are the big, scary birds in the sky, foxes, and humans. I don't know about you, but I am not going to TRY to get close to a opossum.