why did mouse die?

Question
A month ago, I bought 2 (male) mice for my daughter. We went away for the weekend and left their care to our neighbor. when we got back Butterscotch was dead and Oreo was not looking so good.  There are two possibilities, one, there was a huge hail storm while we were gone that was breaking windows and would have been extremely loud and scary, or two, their water was empty (the bottle sometimes empties itself when the mice push shavings against the end.) Maybe the neighbors didn't notice.

What do we do for Oreo now? We gave him water right away and he's eating and drinking.

Do we get another mouse right away? I know they need company and would miss his friend.

How can i tell if Butterscotch died from no water or shock from storm?

Our family is so sad that this happened, poor Butterscotch. Thank you for any advice you can give us.

Answer
Dear Jane,

Butterscotch probably died of thirst.  It is very important for mice to have water.  When I leave my mice for a few days, even with a sitter, I give them two water bottles plus some carrots or celery in case the water gets stuck or runs out.  Also, when the water runs out, it can get in the nest and the mice can get wet and die of cold.  I also put the water bottle over the food dish just in case.  

Male mice usually don't get along unless they were raised together or possibly a father and son.  I'm afraid getting Oreo a friend might end in a situation with two mouse cages.  If you want two cages that's great-- put them close together so the mice can squeak at each other (they do this so high that you can't hear it).  Otherwise Oreo will have to be an only mouse as most males are. This is ok as long as he gets at least an hour of quality people-time a day.  

If you do decide that two cages is a good idea, of course, you can try putting the mice together first.  As long as the chasing and squeaking doesn't turn into bleeding, everything is fine.

I'm so sorry about Butterscotch.  Good health to Oreo.

squeaks,

Natasha