What are dust mites and where do they come from?

Dust mites are often referred to as tiny insects, but they are not. Instead, they are arachnids, part of the large group of eight-legged creatures that includes spiders and ticks.

Several species of dust mite belong to the genus Dermatophagoides, a name that describes in Latin their way of life: They live mostly by devouring the skin cells that human beings shed.

Dust mites are very small; about 7,000 could fit on a dime. They set off allergic reactions when their feces and jettisoned external skeletons are inhaled. The proteins that cause the reaction are now being isolated in the hope of finding ways to fight allergies and asthma.

Dust mites thrive in human clothing, decorative fabrics, upholstery, and especially bedding. Warm, moist sleeping bodies provide them with an ideal environment.

Fighting mites involves cutting off their sources of warmth, food, and water, especially in the bedroom. Vacuum regularly, but wear a mask to avoid breathing in the dust you stir up; try an air filter.

Remove rugs, curtains, upholstered chairs, and other fabric items. Keep mattresses and pillows in mite-proof plastic covers, and use synthetic pillows that can be washed rather than feather pillows.

Launder clothes and bedclothes frequently, preferably in hot water.

Keep temperatures and humidity low, if possible, because dust mites prefer high humidity and temperatures above 68 degrees Fahrenheit.