Mouse avoids wheel

Question
Hi there,
I have had my female mouse for about 3 months now and I estimate she is about 6 months old (can't be sure). She was a feeder mouse and my boyfriend rescued her. She is not horribly aggressive but will bite us, so we can't hold her. The only outside cage experience she has is with her ball. She has always been very, very active (running on her wheel all night long). The last two nights she has stopped. She is eating great, and still responses to me playing with her. She jumps and crawls all over the cage but wont touch her favorite wheel. I'm afraid she is depressed, but it is so sudden I can't be sure. We have taken her to the vet once before( about 2 months ago) for mites but they could not find any evidence of them. She also has never had a mate. Could she be bored? We have just a starter cage that is like 12X6X6? I bought her tubes and a log that she seems to like. But, I did read on a recent post that peanuts are bad for mice, and I feed her one peanut like 2 weeks ago. Is there anything im doing wrong or could be doing better?

Answer
Dear Megan,

If she still jumps and crawls all over the cage, it's possible that something happened in her wheel that scared her.  Occasionally a mouse can hurt itself on a wheel, whether it's falling out of an open wheel or getting caught in a bar wheel.  As long as no other behavior changes, this might be the case.  My mouse Brandy, for instance, used to be crazy about her ball and want to spend several hours in it at a time.  Then one day the ball got stuck somewhere (between laundry and a cord that she had managed to bump over) and I fell asleep.  She was probably stuck for 15-30 minutes and it was unpleasant enough for her that she never wanted to go back in the ball again.  She chewed up my pajamas through the slits, which I figured I deserved!

Does she still move in the ball or does she just sit there?  If she is sick you should see some other signs-- hunched-over posture, fur roughness, mucous, less eating or even much more drinking than usual, not pooping or runny poops-- all the things you have been looking for I'm sure.  One thing to check out as well is whether she seems to have any soreness anywhere in her body.  

12x6x6 is pretty small for even a single mouse.  Even though you let her run in the ball, she still needs space when she is most wide awake at night.  Maybe you can get her a bigger cage-- why not even spoil her with a 2-story wire cage, for such an active little mouse?  Another issue is that a single mouse can get lonely.  This would not be a sudden issue,  but in general she would like a friend.  However, don't get another mouse until you are sure this girl isn't sick.  

As for peanuts, it's a common allergy in both people and mice.  Although many mouse mixes actually include peanuts, I take mine out to be on the safe side.  She would not be reacting now to an allergen two weeks ago.  

Best of health to her!

squeaks,

Natasha