How to Sex Adult Mice
Adult mice can be sexed easily by an experienced person however those less experienced often make mistakes, a particular problem when acquiring mice through pet shops.
The most obvious difference between the two is that the anus and vulva in the female are much closer together than the anus and penis in the male. In the adult male the testicles may be visible.
Mice are sexually mature at 6 to 7 weeks and have a gestation of 19 to 21 days with a litter size of 8 to 12 pups.
Weaning age is 3 to 4 weeks. Population explosions are a common problem and ideally mice should be kept in single sex groups.
Female mice are easier to manage than male mice, who will fight if not provided with enough space.
Controlling a Population Explosion!
If you have a mixed gender pair separate them before the birth of young, as the male will re-mate the female immediately after birth, giving you a very rapid increase in your pet population!
Careful thought should be put into breeding any small pet – there are often large populations of unwanted rodents in rescue shelters or with private rescue centres around the country.