Wikipedia
Ammotrechidae are a family of solifuges distributed in the Americas and the Caribbean Islands. They include 22 described genera and at least 83 species. Members of this family can be distinguished from members of other families by the absence of claws on tarsi of leg I, tarsal segmentation 1-2-2-(2-4), pedipalps with pairs of lateroventral spines, and by males having an immovable flagellum on the mesal face of each chelicerum. The propeltidium of Ammotrechidae is recurved.
The common names used for Ammotrechidae are curve-faced solifugid and sand runner. Ammotrechidae live in arid regions, such as dune and rocky habitats. They are carnivores which feed mainly on other invertebrates. Ammotrechidae have relatively high metabolic rates, which allow them to be voracious predators. They feed by masticating their prey and sucking out the liquids. They are preyed upon by other vertebrates. Species of Ammotrechidae are found to be cannibalistic. Males and females dig shallow burrows for protection and nesting.
The species that are found in North America are found in the South to Southwest and are rarely longer than two inches. Though they can be pests, they are considered beneficial because they feed on "scorpions, spiders and termites."