I heard the same and I also heard that sometimes when they switch to ASFs,it's hard to get them to go back to reg rats and mice so, my point is......u can buy and find rats in many places,always somewhere to go,but u can't just find ASFs that easily...so my point again is,lol..if this guy moves or relocates or just stops breeding his ASFs,what do you do now? What if now your snakes don't wanna make the switch back to regular rats?You need to weigh out all options and think of the bigger picture. This is all the stuff I would think about,but that's me