You might also want to start out with smaller rats that are just a little bit bigger than adult mice, or the snake may be intimidated by the large size. If your snake doesn't take the scented rat the first time, you might also try offering a mouse first and then the small scented rat right after that, while it is still in feeding mode. I have had that trick work going mouse to small rat, as well as live mouse to frozen / thawed mouse.... by slipping them the desired different prey while they are still in that feeding mode after having eaten their usual prey. Good luck!