Well I'm a total newbie at ball python behaviour but I would have to say if it's really young, coming thru gawd knows what at Petco and their suppliers, then into your home, and then maybe not cb as Adam has said....might just be a really scared little snake there.
I'd think that a very quiet environment with multiple hides, minimal contact except for feeding and cage maintenance and hopefully time will take care of this, as long as it's healthy and eating and pooping, etc.
I'm wondering myself tho (experts please chime in) if some BP's are just more aggressive in nature and that's just that. I mean even given consistent excellent care some ball pythons are going to be just harder to handle then others, right?
~~Joanna~~