Mites are in everything that has dust in it, that's why they're called "dust mites", and I believe they eat the dust, which is actually dead skin cells from the people and animals living there. They get into carpeting, pillows, stuffed toys, etc., and can even get into your mattress. That's why it's good to use a mite cover over your mattress and bed pillows, and vacuum them with the hose often. Washing in hot soapy water kills them, I believe, as does storage in the freezer overnight. In fact, it is recommended that stuffed animals get the freezer treatment periodically.