[6] The venom of many Sicariidae species is highly hemolytic and dermonecrotic,[2] capable of destroying red blood cells and causing lesions as large as 1 inch (25 mm) in diameter that take a long time to heal.

Rarely, the venom is carried by the blood stream into internal organs causing systemic effects.

[2] The family was first described by Eugen von Keyserling in 1880,[3] and treated as a subfamily and synonym of "Loxoscelidae" in 1893,[7] though this violates the rules of the International Code of Zoological Nomenclature; the publication of Sicariidae in 1880 predates the publication of Loxoscelidae in 1893, and the older name therefore has priority whenever the two are considered to be synonyms.

The World Spider Catalog treats Loxoscelinae as a subfamily of Sicariidae,[1] though some sources still recognize Loxoscelidae as a separate family (e.g.,[8][9]).

A phylogenetic study in 2017 showed that the African species of Sicarius were distinct, and placed them in the revived genus Hexophthalma.