bullying mouse

Question
I have two mice, a female and a male. I got the female two years ago and the male a year ago. Whenever i have them in the same cage, the male will attack the female and he pulls out her fur. Why?

Answer
Hi Kayleigh,

Some mice just do not get along - there isn't always a reason.  Especially with males, some are overly enthusiastic when trying to pursue females and can seriously injure them.  Whenever you witness actual aggression like this it is a good idea to separate them immediately and not risk it again.  Even if you had two females who were behaving this violently, I would still advise against putting them together.  It just isn't worth potentially losing one of your pets.

Additionally, it's important to remember that female mice go into estrus very frequently (approximately once every five days), during which it is possible for her to become pregnant.  At an age of at least two years old, this would be very unsafe for the female and could have lethal complications.  I would really, really recommend keeping them separate from now on.

If I can help you with anything else, please let me know,
-Tam