Random thought

Where does the fuzzy lint on the bottom of the mice come from? I clean my desk with a microfiber cloth everyday and I clean around the little cushions on the under side of my mouse. Even still, I clean up multiple clumps of fuzziness a day. Every mouse I've ever used has had this build up so I know it's not this particular mouse. I have a theory that little portals open up underneath the mouse when I'm not looking and faeries deposit their used toilet paper. Makes sense doesn't it? I thought so.