Mouse Breeding Question

[Jay_Bunny]

If you keep your males in with your females 100% of the time, how often do your females have a litter? Once a month?

[Stewart_Reptiles]

If kept together females can have litters every 3 weeks

Female mice and rats can get pregnant hours after birthing and gestation is 21-23 days.

[tomfromtheshade]

Gestation for mice is about 21 days.
They come into heat every few days.
If the male nails her on the first go round you can expect new babies in 21-25 days.