I keep both. I had two pet rats before I ever got snakes. I just keep my pets separate from my breeders/feeders, that way I don't get too attached to the snake food. Although my breeders have become my pets and I couldn't kill them off at this point, they will just have to retire until they die of natural causes. Since I don't handle the feeder rats as much they don't really enjoy being held, although I will admit I do scratch or pet them whenever I'm in their cages.

I'm not sure how I do it other than I grew up on a farm in which our "pet" pigs/ducks/rabbits/chickens/sheep etc. were butchered and put on the table for dinner. In fact I have three baby ducks I raised from eggs (in my home) we will be murdering and eating in the next week. Maybe that's how I do it