I use this



Those are the tubs http://www.organize.com/storboxclear1.html

I keep the females individually with their litter at least for the first 10 days once the babies reach that age I sometimes put 2 females together with their litters.

Usually the damage (due to female fighting over babies) and the loss of babies occur during the first 10 days (based on what I have observed in my colony) which is why I make sure that each female is alone with their litter during those first 10 days.