plus if you get them eating chicks they might not switch back to mice or rats very easily. i don't know about you but it's easier to get F/T mice and rats (pet stores, feeder breeders ect) then it is to pick up a chick.

on a side note, a friend of mine got a gerbil for some reason and decided to give it to his ball. he took it, but then decided he only wanted to eat gerbils from then on. and at $12 a pop at the pet store, he was sooooooo glad he switched him after 2 months of trying.