Starting to breed mice

I recently got a month old bp. Attempting to get the right sized hopper, I have stacked up about 7 mice that I am tacking care of. All at this point full grown. I was wondering if they will just start having babies. I wouldnt mind it, since my bp is having a little trouble feeding f/t and all my local pet stores only sell full sized adult mice. If anyone has any experience with producing mice please leave your insight. Thanks

You need quality food ideally 18% protein.

They need to be stress free. The best enclosures for that are opaque tubs.

Do not place more than 1 male with a group of females.

Do no over crowd.

Optimum temps 68/75

Gestation is 21 days.

Weaning at 3 to 4 weeks.

Retire after 5 litters.

Also dont get depressed if you find baby bodyless heads.
It happens.

I breed rats not mice. From what I hear though, you need to watch the room temps. Can't be too hot or cold.