When to separate mom/babies and male/female baby mice

[ratlets]

I work at Petco.  We are only supposed to be getting in male mice... yeah right.  There were two male mice in a tank of who knows how many females. 

I pulled out 4 HUGE pregnant girls.  1 miscarried.  1 delivered today. 

When are mice sexually mature?  When does the mother wean? 

Thanks!

By the way... pinkies are so cute!! Tiny tails!

[MsMagpie]

I just brought home a girl being housed with boys from Petco as well! I was told boys can impregnate mom as early as four weeks, but brothers and sisters don't have to be seperated until five because girls mature later.

[KatnRat]

Separate the baby boys out at 4 weeks. The girls can continue to live with mom.

Although most girls are not sexually mature at 4 weeks, it's just not worth it to risk it (and I've heard exceptions to this "rule"). By leaving the girls with mom, and the boys together- no one is left lonely! Just keep an eye on the boys for any squabbling since often boys will not get along after sexual maturity.  Many boys who live together from pinky-hood do, however, so it's nice to give them a chance at having friends.