Dust mites feed on the dead skin that falls off the bodies of humans and animals and on other organic material found where they live. Though these mites live in many homes, only people who are allergic to them know they are there. Dust mites are second only to pollen in causing allergic reactions. When dust mites grow, they shed their skin. The shed skin and feces are what cause allergic reactions in people.
Allergic reactions range from itchy noses and eyes to severe asthma attacks.
Many people spend much time and money cleaning the air ducts to reduce dust mites. This is not necessary because dust mites need about 70 percent relative humidity or higher to live, and they need food. Areas where people spend much time, like a bed or a favorite plush chair, are prime sites for dust mites. The top part of mattresses containing fibrous material is a favorite place for dust mites during warm and humid times. The deeper parts of mattresses may provide protected areas for the dust mites during unfavorable conditions.