This species ranges from Kleburg and Duval in Texas to central Coahuila south to San Luis Potosi.
The Mexican black-headed snake inhabits moist areas and takes refuge under stones, mountain canyons and desert washes. Tantilla atriceps are nocturnal in nature. This species feed on invertebrates, scorpions, spiders and insects.
The Mexican black-headed snake is a relatively thin snake with adults having length ranging from 5-8 inches. This species has a dark cap on its head and that is the only dark pigmentation found on its dorsal surface. The black cap extends as far as two scales behind the parietals and has a posterior edge that is slightly convex or straight. Some individual members have a line that separates the back of the cap from the other parts of the body. The line is usually light colored. The Mexican black-headed snake has a red or pink ventral surface.
Learn more with Schechter Natural History's Guide to Reptiles and Amphibians