I have a yearling ball python and he has been living on 2 ave size adult mice a week. I am wanting to move him on to rats as my mouse supply is dwindling and I feel it easier to feed one larger meal than two smaller ones. The feeding mice in question are approx 25-35 grams each, making a weekly meal of 50-70 grams. I can order any size rat, but I don't know what size would be best to move up to. I would prefer to buy one size that can last him awhile so I can order 100-200 of them at once since it costs less. So what do you think I should move him up to?