"the small sandvipers"
Sand viper (Heterodon nasicus)
Creative Commons AttributionSand viper (Heterodon nasicus) - Credit: Francis Crawley

There are three species of sand viper: Vipera ammodytes, (a.k.a. the nose-horned viper), Cerastes vipera, (a.k.a. the Avicenna viper), and Heterodon, (a.k.a. hog-nosed snakes).

The Heteredon nasicus is the only species of sand viper native to North America and northern Mexico. It is known as the hog-nosed snake on account of its upturned snout, which aids in digging in the soil. Unlike the venomous Vipera ammodytes and Cerastes vipera, the Heteredon is harmless.