Reptile & Amphibian Forums

Hi all,

Have been lurking for a couple of months. I have 2 females and 1 male mice. Both females have had litters now and I have since realized that I do not have enough babies to feed all my lizards. I have tried to add another female into the mix without luck. The others will not accept an outsider. The local reptile store suggested I keep one of the babies for breeding. A little inbreeding wouldn't hurt much. However, at what age can you sex a mouse and how do you do it? All of the babies look alike to me! LOL

Any help would be appreciated.
Donna

>>Hi all,
>>
>>Have been lurking for a couple of months. I have 2 females and 1 male mice. Both females have had litters now and I have since realized that I do not have enough babies to feed all my lizards. I have tried to add another female into the mix without luck. The others will not accept an outsider. The local reptile store suggested I keep one of the babies for breeding. A little inbreeding wouldn't hurt much. However, at what age can you sex a mouse and how do you do it? All of the babies look alike to me! LOL
>>
>>Any help would be appreciated.
>>Donna

The simplest way is if you see nipples they are girls. Once they mature you will certainly be able to tell...but by then if it is a boy the dad will be trying to kill it.
-----
Sonya

It's actually not that difficult...wait until they're a week or so old, as it's hard to tell with newborns.
Lay them out, and compare the distance between the anus and the urinary opening. In males they will be noticeably further apart than in females. I've never noticed that females have particularly pronounced nipples as compared with males. By looking at several babies, you should find that you're able to tell the genders apart by judging the distance.

The nipples on the females are only particularly pronounced when they first reach fuzzy stage. (And after they have pups when they are nursing!)

At the pinky stage you can do the comparison on the space between the uerethra (SP??) and anus.

At fuzzy satge any you can see nipples on are females. (I imagine males have them, but you can't see them, if you see nipples on a fuzzy it is a female)

At hopper/juevenile size pick each up and give a little squeeze while looking at the backend of the mouse ~ younger males can suck their testicles up when frightened so you have to give a little squeeze to pop them out and see (DON'T Squeeze hard! And wear gloves! Every mouse in the world is gonna bite when you snatch it up by the tail and try to squeeze a pair of testicles out!) )

Once they are adults males testicles are large enough they can't suck them in very far so you can just grab them by the tails and look, you'll see which are males!