Originally Posted by Noah

Males tend to fight, and due to this are generally kept solo. Some will live together peacefully, but they are usually litter mates or very young males that have been introduced, but unfortunately there is no guarentee. Males also have a stronger scent, they mark their territory often and lots *L* (wether that territory be you or the cage). Males kept in groups tend to try to 'outstink' each other...and it can be VERY strong *LOL*. Due to the stronger smell/territorial thing, males are harder to home. Shame really as most of the smoochiest mice i have are boys.

Some females have these issues as well, but it is usually a rare thing in females