mice are healthiest if you don't breed them til 10-12 weeks old and no older than 8-9 months old, i do the icecream container thing too, but tea boxes cracker boxes, anything like that is good. try to avoid taking all babies at once(distressing) and expect babies every 3 weeks. keep in mind how you're going to euthanase them as this is what people have the most trouble with, good luck