Reptile & Amphibian Forums

So i bought a female mouse that had babies a little while ago and they are about 4 weeks old now and there eating and what not on there own and i was wondering if i can seperate the babies yet and allow the female to be breed again? Also how can i sex the babies so i know which are females to keep and breed?

at 4 weeks of age they should be nearly completely weaned. 4-5 weeks is good with mice. The males should be very obvious now, their testicles are out and should clearly be noticeable as a bulge near the base of their tail.

You do need to have the males separated from the females by the time they are 5 weeks old or a bit sooner. At this age males do become sexually mature and can impregnate females.

Females should not be bred till they are at least 8 weeks old, 12 weeks is better.

The mothers of your babies should get a week or two of rest after all their babies are removed from their cage. This ensures energy/food going to produce milk etc is redirected to her. You can breed them anytime now, but it all depends on how fast you want to produce mice. Giving them more time between litters ensures you can find homes for the babies. You may find you have alot of mice left over from the litter and as they get older it may be more difficult to find homes for them. It is so easy to wind up with too many mice even from a single pair of mice to start.
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PHLdyPayne

One further note about sexing I forgot to mention above. If you pick up the males by their tails, often they suck in their testicles so you can't really see them. Under the tail between the anus and penis, is a much greater space than between the female's anus and virgina. You can also notice a 'tuck' of skin on the male in that larger space with forms a sort of wrinkle when the 'boys' are pulled into the body.

Typically if you let the male mouse walk on your hand for a few seconds the 'boys' will come out and you can easily see them.
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PHLdyPayne