The night snake (Hypsiglena torquata) is a species of rear-fanged colubrid. It is found from British Columbia, Canada through the western United States to Mexico. Subspecies previously recognized within H. torquata Hypsiglena torquata affinis Boulenger, 1894 – Boulenger's night snake Hypsiglena torquata baueri Zweifel, 1958 – Cedros Island night snake, Bauer's nightsnake Hypsiglena torquata catalinae W.W. Tanner, 1966 – Santa Catalina night snake Hypsiglena torquata chlorophaea (Cope, 1860) – Sonoran night snake Hypsiglena torquata deserticola W.W. Tanner, 1966 – desert night snake Hypsiglena torquata gularis W.W. Tanner, 1954 – Isla Partida night snake Hypsiglena torquata jani (Dugès, 1866) – Texas night snake Hypsiglena torquata klauberi W.W. Tanner, 1944 – San Diego night snake Hypsiglena torquata loreala W.W. Tanner, 1944 – Mesa Verde night snake Hypsiglena torquata martinensis W.W. Tanner & Banta 1962 – San Martín Island night snake Hypsiglena torquata nuchalata W.W. Tanner, 1943 – California night snake Hypsiglena torquata ochrorhyncha Cope, 1860 – spotted night snake Hypsiglena torquata tiburonensis W.W. Tanner, 1981 – Tiburón Island night snake Hypsiglena torquata torquata (Günther, 1860) – collared night snake Hypsiglena torquata tortugaensis W.W. Tanner, 1944 – Isla tortuga night snake Hypsiglena torquata unaocularis W.W. Tanner, 1944 – Clarion Island night snake Hypsiglena torquata venusta Mocquard, 1899 – central Baja night snake Most of the following information refers to various species within Hypsiglena. Morphology and physiology Description Total length is 12–26 in (30–66 cm). It is pale gray, light brown, or beige in color, with dark grey or brown blotches on the back and sides. The night snake's head is rather flat and triangular-shaped and usually has a pair of dark brown blotches on the neck. It also has a black or dark brown bar behind the eyes that contrast against the white or pale gray upper labial scales, and the pupil of the eye is vertical. The belly is white or yellowish. Females are usually longer and heavier than males. Venom Although the night snake poses no threat to humans, it is slightly venomous and uses this venom to subdue its prey. Distribution and habitat The night snake has been found as far north as southern British Columbia, and as far south as Guerrero, Mexico. The eastern range of the night snake extends to Texas. Still, not much is known as far as population densities and exact range due to the highly cryptic nature of the night snake. The night snake is