I've found myself with a problem of my own making. My most recent litter is 7 days old today, and I was confirming sex on them. I did an initial cull a couple days ago, and because I am more interest in retaining a buck than a doe from this litter, I took out more does than I normally would have. But I thought I had left myself with at least 3 girls. Turns out I only have 1 girl left. I've always left my moms with 4 pups, to make sure she can continue to produce milk. But if I do that now, that'll mean I have to keep 3 boys through weaning. I have only room for 1 boy, and I hate culling once the eyes open... I've read of successful litters of three or less pups, so I'm wondering if I should risk culling this litter down to two or not. They are petshop derived mice.