Introducing rats

Ok so I read rats are more nutritious than mice, and I'd like your opinion on when is right to switch from mice to rats. My bp is only 10 months, she's currently on 3 inch frozen mice (don't know what you class that as?). What equivalent size rat should I ask for at the exotics shop? Many thanks!!!

Actually rats and mice are both about the same nutrition wise. Just avoid XL rat or mice as they are fatty and fat is not digested well by snakes. The main reason to switch to rats is because they come in a much bigger size than mice so it is cheaper to feed that way. 3 mice is a lot more expensive than 1 small or medium rat. As for what size, what size are the mice you are buying labeled as? Large? From the length, im going to guess large mice which is about equivalent to a rat pup which is between fuzzy rat and weaned rat. Depending on the store, the size may vary. The store I buy from sells pups and fuzzies as the same thing. You just say either large fuzzy or small fuzzy. Your BP might be able to eat weaned rats too. But a 3" mouse is the equivalent of a rat pup to answer your question.