When Do Mice Reach Sexual Maturity

If you have pups, or baby mice, you will need to know – when do mice reach sexual maturity. It’s incredibly important to separate pups before they reach sexual maturity. Otherwise you risk having more baby mice and also inter-breeding.

When Do Mice Reach Sexual Maturity

Mice reach sexual maturity at about four to six weeks of age. Male mice can breed from as young as eight weeks old, so you can see how quickly mice can breed and start to multiply in numbers.

When the breeding is under your control it’s recommended that you do not breed from females until they are at least twelve weeks of age. This increases the chance of stronger litters and healthier pups.

Male mice will typically stop breeding after they reach one year old. You should stop females being able to breed at a year maximum. These are further precautions to ensure safe litters.

Sexing Mice

When mice are more than two weeks old you should be able to see the nipples on female mice. This is the main way you can tell the difference between males and females.

Another way to tell by looking is to look at the genitalia on the mice. Male gentiles are a lot further from their anus than females. By looking at mice of each sex it becomes fairly obvious what the sex is.

Keeping Males and Females Seperate

As owner of mice it’s responsible to keep the male and female mice separate. If you know you have both sexes you should always separate them into individual cages if you are not deliberately breeding them.

Females will live happily together in almost all instances. Males can fight on occasion, so this is something you need to keep a closer eye on.

If you have had pups then remove them before they reach sexual maturity at around four to six weeks of age.