you really shouldn't have any snakes sharing a cage period. that is a great way for one to kill the other, or share some fatal illness. If one gets sick or gets mites, i can gauruntee you will have to treat the other. it is hard to tell who poops when, so if one is ill, you may think it is not. Ball pythons can and do eat one another, although it is pretty rare. I wouldn't risk their health or happiness- snakes will pile on top of each other as a form of dominance behavior, and the subordinate (usually smaller) animal is definately stressed even if YOU can't tell. snakes are not like people, they will not tell you if something is wrong and when you do figure it out, it's usually too late. Unless the cage is massive- five feet by five or more, they are probably competing for heat sources and hiding places, you don't want to give them that added stress of competition. in the wild, the snakes are able to avoid one another, in a cage they have no choice, which causes stress.