Denna sida på svenska. The mouse to the left is a female mouse. Her name is Clairehild, and she is a special favourite of mine, I really love her nice temperament.
The art of sexing mice - knowing which mouse is female and which mouse is male - is something you have to learn for yourself. Never trust a pet shop to know this! If you do you will probably get the wrong gender...
The sexual difference depends on how young the mice are.
But if you are familiar with sexing rats you will not have
much trouble, since these two species are a lot alike. Adult mice are always easy to see the difference in.
The mouse to the right is a male. His name is Primus.
Newborn: Turn as many newborn babies as you can safely hold upside down and compare closely. Especially you should concentrate on the distance betsween the genitals and the anus, which is longer in males, and the size of the genitals, which is bigger in males.
Around three weeks may be the hardest time to sex mice.
At over 4 weeks the testicles are usually seen, a sure sign that it is a male!
If the baby mice has been sick or are sick they might be much harder to sex.
Copyright Eva Johansson.
Last update: 3rd of December 2007.