Spider mites are tiny arachnids that feed on plant sap and can cause serious damage to gardens and crops. They belong to the Tetranychidae family, which has about 1,200 species. Spider mites have eight legs, two body segments, and piercing-sucking mouthparts. They can be green, orange, red, or yellow, depending on their age and species. Some spider mites change color in colder weather. Spider mites live on the undersides of leaves, where they lay eggs and spin protective webs. They thrive in dry and warm conditions and can reproduce very quickly. Some spider mites die in winter, while others survive by hiding in bark cracks or garden debris.