Sounds to me he may have learned, "I'm out of my tank, its time to eat". Try feeding him in his tank for awhile. Could be many other things, but that is my first guess. I would say 90% of the ball pythons are super mellow. There is another 10% that can be a pain. Whatever you do, if he acts like that don't put up with it. Pick him up. He may try to bite but if you pick him up right it won't happen. Once you are holding him do not put him back until he relaxes. Once he does immediately put him back in his cage. He will most likely learn. That said, i have one animal that nothing has ever worked on. She bites, she hisses. I love her anyway. She keeps me on my toes.