Def. set everything up before hand. I think rats are fine over mice. As long as you buy the right sizes. I got the first three sizes at the my local show. Pinkies and fuzzy rats will be good depending on the size. fuzzy will last up to 200g. There is a food chart on here to go by. Not sure how to grab it. Google ball python food chart will come up. Gives you both mice and rat sizes.