They live in deserts and arid regions of the Neotropics, and females use a mixture of sand and silk when producing egg sacs.

Sicarius spiders can grow up to 1 to 2 inches (25 to 51 mm) long, and have six eyes arranged into three groups of two (known as "dyads").

They lack the characteristic violin-shaped marking of the more well-known members of its family, Sicariidae the recluse spiders.

[1] Like all recluse spiders, these produce a dermonecrotic venom that contains sphingomyelinase D, an enzyme in the sphingomyelin phosphodiesterase family.

The venom causes bleeding and damage to many organs of the body, though only S. ornatus and a few others have been proven to be extremely toxic on the order of Hexophtalma hahni or several other African sand spiders.