A mite is a tiny creature, so small you can barely see it without a microscope. Mites are related to spiders and ticks, with eight legs and round bodies smaller than the period at the end of this sentence. They live almost everywhere: in soil, on plants, in water, and even in the dust in your house. Some mites eat dead skin cells that fall off people and animals. Others live on plants or help break down dead leaves in forests.

Most mites are harmless, but a few types can cause problems. Dust mites in bedding can trigger allergies and make people sneeze. Chigger mites bite people in grassy areas, leaving itchy red spots. Some mites damage crops by feeding on plant leaves.

The word mite also describes anything extremely small, like when someone offers “just a mite” of help (meaning a tiny bit). You might also hear the phrase “a widow's mite,” from a Bible story about a poor woman who gave two small coins. In that context, a mite was an actual coin worth almost nothing, but the story celebrates how even a tiny gift can mean everything when it's all you have.