Because the female is genrally more dominant . If u want to breed them , consult a local breeder first for advise as you could be putting your rats in danger.
A mouse can be either male or female.Fun Fact: In one month a female mouse can breed and the baby mice will breed and produces at least 100 mice a month. Next month will be 200 then 400 the 800 etc!
You can look at the distance between the anus and the genitals. This distance is shorter for a female. If your mouse is older the testicles will start the show on a male.
Hi my name is Melina and i am 9 years old.I think it would be best to start out with a female because if you have a female hamster of gerbil or something of the rodent family if you have a male and...