Mites are a type of minuscule bug that are related to ticks and spiders. They are usually found in warm, moist environments and feed on organic matter such as dead skin cells, fungi, and plant material. Mites are very small, ranging from 0.2 to 0.4 millimeters in length, and can be difficult to spot with the naked eye. They can cause skin irritation and allergies in humans, and can also damage crops and stored food products.