I used to think of some of my longer-term breeder rats as more pets than feeders. Rats make awesome pets when you invest the time into the right one. Some are fearful or super defensive from the get-go; others will happily sit on your shoulder and be handled. I had one big blue male who was a complete kitten when handled. It can be done! I would just be sure not to have the rats within view of your snakes' cage, and to wash hands thoroughly between handling animals.