A long time ago when my children were young and I was consumed with raising them and taking care of the home, I was a pet store with my sister-in-law when they showed us this cage with two mice --a male and a female--and told us they had been together (now I don't remember how long--and at that time I didn't know they only live about a year) and she made this little ratcheting sound all the time. They said she had always done this and wasn't really sick from it--but for some reason never got pregnant. We couldn't resist (and my sister-in-law was living with us), so we bought them. We named them Mr. and Mrs. Ratchet (because of the noise she made)--I didn't know how to do research (or there wasn't much at the time) on the computer, so I had just taken the pet shop people's word (I am soooo much wiser than that now)--The mice were so tame, especially Mrs. Ratchet. After a month or so, Mr. Ratchet got sick. I went to the vet for him and they gave me an antibiotic for him. One day we found him dead and Mrs. Ratchet had eaten one eye and one ear (now I know why--then we thought ewwww). Then the vet told me that a lot of times mice carry strep throat without having it--and that she gave it to Mr. Ratchet. And I mentioned that since we had had her, our whole family kept getting strep throat (and we usually NEVER had it even with the kids in public elem. school). He said that was where we were getting it and the best thing to do was put her to sleep (death). Being younger and ignorant, I think, I followed his advice too. Now this and many many other reasons and some events are why I don't take anyone's word--I read and read and read and talk to lots of people who have the animals and try to find out the REAL stuff.