ok for the rats i suggest you use a rack system as you are going to do. But i would customize the rack to fit what you need. such as if you were short you could make a rack not so tall. or if your tall your could make your rack tall. Also it depends on how much space you have. if you need to conserve space you should build a rack tall rather then wider. also if you are interested you could add a watering system. i haven't had experince with either. but soon. also personally love albinos, to breed and give my snakes. to me they look so much better. but hooded are cool also. but good luck on your rat breeding:gj: