Well, you can do like I and a few other folks here do, and just feed mice. I have adult females(2600g+) on mice and they do great.

I have pet rats as well, 24 of them to be exact(with more on the way), and cannot bring unquarantined rats into my house. I also have a few snakes that will not touch rats with a 10-foot pole(you can actually see them wrinkle their noses, hehe). So I breed mice and it works out well for me.