I had a small colony of mice 5 females to one male. Each have separate tubs unless the male needs to impregnate them otherwise the male has his own tub too. This helps me to control the numbers and give the moms time to re-cooperate after birth and raising. I had one mom when I first started who ate her litter... :Oneedless to say she got fed off after that:snake:. Not too many other issues after that.