The Tetrablemmidae are a spider family with 126 described species in 29 genera that occur throughout the world tropics. They are sometimes called armored spiders. The family Pacullidae, with the only genus Paculla, has been incorporated into this family in 1981. Most tetrablemmids have been collected from litter and soil, including soil in epiphytes; some live in caves. Some cave species, but also some soil inhabitants, show typical adaptations of cave spiders, such as loss of eyes and weak sclerotization. Tetrablemmids do not seem to build webs.