It depends upon whether or not they continue to amuse me... Rosencrantz has a better survival rating, because she likes to be picked up and petted, she doesn't stink, she has longish, satiny fur, and she made friends with gremliness who would be most disappointed if her friend Rosie came to an ignoble end. Since a Rosencrantz without a Guildenstern is kind of lopsided, I've kept him also. This would change on a mere whim, since they're still mice and therefore little squeaking prey animals by design, except that rialian thinks that would be hideous and stuff.