I'm sorry, but like April said, those mice will not stay in those drawers. With the lack of ventilation, you are going to have to clean those tubs every 3 days. Mice urinate CONSTANTLY and their urine is very concentrated and ammonia filled.

Ever stick your head in a pine bedding-filled urine-caked enclosure with no ventilation before? You will never want to again if you do. It makes your eyes water, your nose burn and is just disgusting. It will damage the mices' lungs irreversibly and there go your breeders(and future litters). They don't breed well when stressed, and not being able to breathe properly stresses them out.

I recommend just getting normal plastic tubs that are wider and longer than they are tall, replacing the majority of the middle of the lid with wire mesh and using them that way. To help cut down on the urine smell, put a few drops of vanilla into their water bottles.

I hope this helps and I did not come off as rude. You want babies, and the way they are set up, you will be pulling your hair out as the constant changing of bedding and loose mice will drive you bonkers. Oh, and pine bedding should not be used in an enclosed space. The phenols are not good for their lungs or their skin, but what can ya do. You need alot of ventilation when using pine so as to not damage their lungs. The combined smell of the pine shavings and their pee is enough to gag a maggot. I use aspen, and even letting a 10 gallon tank with 3 mice in it(1 male) go for a week just about makes me gag. They STINK, so as much ventilation as you can provide, it will really help.