The inventor of the microscope, Anton van Leeuwenhoek, reported in 1694 that mites live in dust. Now, more than 300 years later, it is an established fact that dust mites can be found in house dust all over the world. Dust mites are not insects but are more closely related to spiders and ticks. There are two common dust mites, the American house dust mite (Dermatophagoides farinae) and the European house dust mite (D. pteronyssinus). Due to their very small size, these dust mites are not visible to the naked eye. They live in bedding, couches, carpet, stuffed toys and old clothing. 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.
Habits and Habitats
Dust mites do not live in air ducts in homes. Many people spend much time and money cleaning the air ducts to reduce dust mites. There are a number of good reasons to keep ducts clean, but this is not one of them 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. Clothing is used by dust mites as a means of transportation from room to room or even from house to house.