well, here's my take on it...
you stated you'd like to seperate out females, well, for me, that's what I do with my rats, when they are showing heavily, I pull them out of the breeding tub and give them their own little tub to have and raise their babies in. But with mice, here's what'll happen, you'll remove the pregnant female, she'll have her babies, and raise them up happily, then you'll put her back into the breeding bunch...and chances are good, something's going to die! Cause mice are VERY territorial, and some lines of mice turn into little cannibals and attack anything that smells strange. I've always cleaned mice by taking mice out, putting them into a five gallon bucket while I cleaned out their cage, and put them back in, and have had males attack their own females, cause the scent of the last mice in that bucket set them off! And yes, I've had the gentler mice, that just scurry around a few times, and squeek at each other, but it always upsets the whole breeding cycle for mice, and they are really only their best for about six to seven months before breeding quality goes downhill. So my recommendation to you, is only keep one male, and the group of females together, ALL the time. The way I run it in my group, is I check to see how the babies look. If everyone is fat and happy, I let them grow up or whatever I need to feed. Sometimes you can have several litters of babies which get to large fuzzy size, and suddenly another female has babies. I don't like to make pinks compete with obviously larger babies. It can be done, but you usually get tinier babies out of the pinks. I like to see large weanlings, cause ultimately, those weanlings are one of two things, food for snakes, or future breeders. And why not make sure the future breeders and food for the snakes are the best you can do? You might find you have to feed less to your snakes cause the meals are bigger and more robust. Plus using the biggest healthiest of your weanlings for future breeders is a plus. I also try to keep track of larger litters. When a female who has been a great producer suddenly has a large litter of 15, I watch closely, to see that she's a good mother, and depending on my need of pinks or fuzzies, I pull all the males out, as I always use more females, obviously! So this way she's only got her daughters to raise, who hopefully have those high production genes. And they are held back as breeders. So yes, this intensive culling of pinks and fuzzies in my colony makes me need animals that eat small mice...well, my collection of animals has mouths to take on those babies! If you've only got adult animals, you could let nature take it's course and just let the mice raise all the babies best that they can. But I notice I can get several to a whole litter of runty under sized babies that way. I know I spend more time on my colony of rodents than I do with my snakes! But thanks to my love for animals...odd...I love animals yet I feed and cull! But thanks to my love of animals I enjoy breeding and raising rodents. I have great fun with the genetics of mice. I have plain white albino mice, but also have a line I call Tiger mice. They have a solid base color, with streaks of darker color, shades of black, in that solid color. So I can have an off white mouse with darker shadings, or streaks in their hair coat. Or a gold mouse with streaks. I know I well answered your question, and hopefully more. Good luck with your mice, and hopefully you enjoy them as much as I do mine! And oh, have what I call an overstock cage. I have two, one for males, one for females, and wean those babies as soon as they look like they can be weaned. Experience will help teach you this. You don't want them in with the adults longer than they have to be, or they are just taking away from the younger litters in my experience.
Russell Keys
Keys Reptiles