Normally with my litters I wean them at 4 weeks, as long as they seem healthy (I've had a premature litter, and left the survivors in with their mom for 5 weeks). I'm good at sexing, and double check anyways because I've had a couple sneaky males in the past. However, even with all of this I currently have a grow out tub full of pregnant young females. 11 pregnant girls, a good deal younger than I would choose to breed them. I remove the male from my breeding groups once I see the moms swelling, so the culprit has to be one of the boys from the litter.

Especially since I separate them a little early, this is kind of frustrating. Anybody else been plagued by an early-blooming litter.... or want some baby rats next month?