Help with new mice, please!

Question
Hi, I think I might have a problem? I recently got two baby (probably about month or two old) male fancy mice. To make it easy I'll use their names, Rusty and Charles. They're brothers from a respectable person who thought they had two female mice but ended up having a male and female so the babies were an accident. Anyway, today I held Rusty and played with him a moment to try to tame him. Afterwards, Charles was grooming Rusty and randomly bit his ear and scratched his back! The brawl lasted all of a millisecond but it scared me senseless. I'm nervous it will happen again and it will last longer. They seem fine for now, they're sleeping together and everything. Was the bite due to the scent of me? Or could it be something else?

Also, I've noticed that rusty is significantly smaller than Charles. When I got them they were the same size. Do mice develop differently?

And one last question, my apologies. Charles is always running on his wheel and often stops and gets off when rusty goes on but rusty wont run on it at all. He does the same in the ball, Charles will run but rusty will not. I hope you can help!

Answer
Hi Shelby,

Uh oh. For the most part, male mice have to live alone. They usually fight, and they will fight to the death. You are probably going to need two cages. They should be near each other so the two can still communicate, which they do in a frequency humans cannot hear. You have only a short time to get the cage before the brawls may become serious.

Yes, mice do have very different body types and personalities from each other. That explains both the size and behavior differences. Do not put Rusty back in the ball. If he doesn't like it, it is very unpleasant.

You and your friend should go to the Fun Mouse site (addy in my profile) and read all about mice. There is a terrific page on sexing too. Never trust a pet store attendant!

Have fun with your little guys!

Squeaks n giggles,

Natasha