A small, thin, snake with a flat head and smooth, shiny scales. The top of the head is dark brown or black, with a faint light collar between the dark cap and the body color which is brownish or beige and unmarked. This collar may or may not have a border of dark dots. The dark color usually drops below the mouthline behind the corner of the jaw.The belly is whitish with a reddish stripe that does not extend all the way to the edge of the ventral scales. This snake uses a mild form of venom to immobilize its prey. This venom is considered harmless to humans. One of the smallest snakes in California, about 3.5 - 15.5 inches long (9 - 40 cm).

Occurs in grassland, chaparral, oak and oak-pine woodland, deserts. Along the rocky edges of streas and washes. Often found beneath rocks, plant debris, and other surface cover.

The known range of this snake in California and elsewhere is spotty due to its secretive nature. Its range is probably less disjointed than the records show. It occurs along the coast of southern California, east and north to the desert side of the mountains as far as Whitewater Canon, and north through the San Joaquin Valley to the San Francisco Bay where it has been recorded just south of San Jose and east of Livermore. Occurs in disjointed locations in Baja California south to the cape. From near sea level to about 4,000 ft. (1,219 m).

Not well understood. Eggs are laid, probably in May and June.

Millipedes, centipedes, and insects.

Secretive -spends much of its time underground or underneath surface objects. A good burrower, able to disappear quickly into loose soil. Occasionally found active on the surface at night on roads, especially after rains.