I don't think they are comparable at all, except for the fact they both produce animals. GOOD ball python breeders pay close attention to their snakes. I'm sure there are bad breeders that have sick snakes with mites and stuck shed ect... Puppy Mills do not provide proper care for their animals, breeders do. Ball pythons can benefit from a more dynamic habitat, but they can still thrive in a rack system when given the proper attention.(I think it gets more questionable with more mobile snakes like bulls or Kings). Remember guys, all the morphs and combos we love are made possibly by the breeders.