We had a possum trapped in our toolshed for about a week. It finally got brave enough to attempt an escape but I think Chopper spotted it after it had managed to get about halfway around our backyard fence. I don't know how long the possum had been stuck in this one spot with Chopper beneath him standing guard but it was probably for a few hours. Once we got Chopper away from him he wandered off on his own. He made a big mess on one of the shelves in our shed by tearing up a bag of charcoal. That was fun to clean up.