I've read several articles that state a year, though my google-fu is now failing me. Since corn, milk, king, garter, etc. snakes don't seem to get IBD I would get one of them if I wanted to keep a snake as a pet, and avoid boas and pythons. Also, for pets I prefer my king snakes over my ball pythons as they're more active during the day, easier to keep, and they're voracious eaters.