mouse bully

Question
I recently got 2 mice to be companions for a mouse that had a companion up until she recently passed away. One of them gets along fine with my original mouse, the other has been attacking and chasing around the other two (Almost non-stop if they are not sleeping) they are in a large aquarium and have plenty of hiding places, food and water... The mean one has red eyes the other two have black eyes (does that make a difference) I don't want any of them to get hurt but cannot get a second cage, is there something I can do or should I try to return the bully?

Answer
Hi Heather,

I'm very sorry to hear about your loss.  How long ago did you purchase the two new girls?  It usually takes a few days for a pecking order of sorts to be figured out (it sounds like the bully is trying to make sure everyone knows she is the boss), but after that it should settle.  If it has been several days and she is still constantly harassing them, I would consider exchanging or returning her so everyone can rest a little easier, her included.  There are a few things you can try with keeping her, such as removing things to fight over, rearranging the cage, changing the bedding, or even trying a tiny, tiny dab of vanilla extract (real, not substitute) on each mouse's bottom, but if you are really concerned they will get hurt, you may not want to take any risks.  Pet shops generally understand that not all pets get along and should have a return policy that you can ask about before making your decision.

The eye color doesn't make any difference at all.  All it means is she drew the right genetics for pink eyes instead of black, but it has no link with her behavior or temperament, it's just how she looks.

In the end it comes down to your judgment, so that all the mice can figure out how to live happiest.  If there is anything else I can help you with, please let me know and I'll do my best.  Best of luck!

-Tam