I really haven't documented it to say for sure, I currently just let a few rats a week creep into small size. They are the ones that go to a local breeder in my area that does ball pythons, she asked for smalls. All the ones that I feed and sell to pet stores go at the weanling stage. Anything extra get frozen before getting any bigger than 60 grams. I do know that a tub with 6 small rats will eat more in one day than a tub with 4 huge breeders in it.