They do not have antennae. Some common species are the two-spotted or red spider mite. These mites have two spots on the back and have tail-end spots in some species. They may be clear, orange, or reddish. The clover mite is reddish brown or grayish, and are flat with long front legs.
Some mites are beneficial because they feed on plant mites.
Predatory mites occur on infested plants, but are larger than their prey and move more quickly. Some may be purchased for biological control. Spiders resemble spider mites, except they are larger and have two clearly distinct body regions with a thin waist between. Most spiders are predators of insects, and thus are beneficial. One common poisonous species is the black widow spider.