I give my extras to a local pet store, to sell as pets or feeders. My breeder rats are all pets. They're remarkably intelligent, personable animals - unlike mice, which are just annoying, though I've had those as pets as well. I recently discovered that I have a Retic and a Burmese breeder near me, so any rats that get too big for my BP's will have a place to go...

Just be sure you don't make the same mistake I did, and put your male(s) in with all of your females at once. I had four rats give birth within a few days of each other, which was waaaay too many rats all at once. It worked out, sort of, since my breeders (purchased, unhandled, unfriendly and aggressive) have now been phased out and culled, so that I can raise some of their offspring to be more tame and replace them. Though the male I ended up keeping... he's pretty mellow. I'm still trying to figure out how I got Cream, Siamese, and Siamese Hooded rats from black Berkshire parents. Rat genetics completely elude me.