replacing mouse companion

Question
I had two fancy female mice, Cookie and Creme, but I had to put Creme down because of a tumor.  I was wondering how to introduce a new mouse, and how long to wait after Creme has been gone (she was just put down earlier today).

Answer
Dear Brittin,

Get a new mouse as soon as you can. Mice don't like being alone, and she will be depressed both about losing her friend and about being alone.  To avoid this I always keep three mice, so that when one dies the other two have each other for comfort until I replace the third mouse.  So I recommend you get two new mice.

When you get the mice together, be sure to put them in a fresh cage which does not smell like the first mouse.  This way it is neutral territory.  The two mice will likely want to decide who is the 'A mouse' and so they will chase each other.  When one chases, the other runs and squeaks.  This doesn't mean she is hurt.  It's just communication.  I don't worry about chasing and squeaking unless there is blood.  Sometimes I remove a mouse for a while to give them a break. You can also tap on or rattle the cage, or blow on the mice, to get them to stop for a  bit.

If the new mouse is young-- and it's fine to get a baby-- you will notice that sometimes the little one will stop and turn around and stand up on her hind legs to be sniffed by the other.  She may squeak at the same time.  This means she is offering her life to the other mouse-- saying something like 'I'm only a baby, you can kill me if you want, I throw myself upon your mercy!' This may not end the chasing right away but it is a good sign.  Hopefully the chasing will end within a week or two.  

Getting two new little ones is a good idea also because then each one only gets chased half the time.  

Good luck and have fun!  

squeaks n giggles,

Natasha