The oonopid spiders (family Oonopidae) include about 450 species in about 65 genera worldwide. They are generally tiny (1-3 mm) haplogyne araneomorph spiders. Some have hardened plates (scuta) on their abdomens. They often resemble mites, because of their small size and the fact that many species are reddish. These spiders are seldom seen by people as they are both too small to bite and too small to be easily noticed. Generally, oonopid spiders are found under rocks and in leaflitter.
References
- How to Know the Spiders by B. J. Kaston. Dubuque, 1953.