The range of the nightsnake, Hypsiglena torquata, includes most of Mexico and much of the western (especially the southwestern) United States. In Utah, nightsnakes are relatively common in the state's desert regions. Within its range, this species inhabits arid and semi-arid desert flats, plains, and woodlands; areas with rocky and sandy soils are preferred. During cold times of the year, nightsnakes seek refuge underground, in crevices, or under rocks, and become inactive.
Female nightsnakes lay a single clutch of two to nine eggs during late spring or summer. The diet of the nightsnake consists primarily of lizards and lizard eggs, although snakes, frogs, insects, and salamanders are also consumed. Nightsnakes subdue their prey with venom injected by large teeth at the back of the upper jaw.
Nightsnakes are pale gray or light brown in color, often with dark blotches on the back of the neck and dark spots on the back and sides.