I have been using duke coon traps to get the raccoons in my yard that have been flipping up the grass. Now, every Raccoon I have trapped has never tried to bite its own arm off in order to break free from the trap. They have been in the trap for many hours while I was sleeping, but they never even think about biting it off. However, when I accidentally trap a squirrel, it bites its own arm off after only about 10 minutes! Why?!