I'm going to keep all the girls, and put them in the tank with the younger male and female (Triscuit and Cookie). I wont keep the males, though. I don't have anywhere to put them, and I'd have to buy a separete cage for each of them. And then I'd have to buy girlfriends for them so they won't get lonely. But the girls I can just put in with the other two, so I'll keep them.
Well it said on a website that mice are good fathers and help with the babies, and only need to be removed a couple days before the female gives birth, because he will try to mate with her then. Another website said that since mice are very social, taking out the father can increase the chances of cannibalism