I'm already looking for the next "pet" rat, but so far, haven't found any that strike my fancy that seem to want to interact much.
I did just discover that I've had TWO males in with two females. Kind of wondered why production was always slightly lower in that bin. Don't ask me how I missed the giant testicles... I guess I just assumed whichever male I held was the only male and never checked to see that the other three were all females. No telling. They haven't been fighting at all, but I pulled the one anyway.
I appreciate all the advice and help, you really are so willing to advise on rodent stuff. And you're right, the ones I've really loved always seem to die before old age can get to them.