Sidewinder, also known as horn viper, is one of four species of small venomous snakes that occupy North America, Africa, and the Middle East deserts, all of which use a creeping "sidewinding" form. The sidewinder is a rattlesnake (Crotalus cerastes). There are small horns above each eye in this pit viper (subfamily Crotalinae), probably to prevent sand from covering the eyes while the snake is buried. In the southwestern United States and northwestern Mexico (see Sonoran Desert), where it feeds on mice, it is a nocturnal resident. Adults weigh little more than 50 cm (20 inches) on average, but can exceed 80 cm. Sidewinders in the fall give birth to 5-18 youngsters. Any people have lived almost Twenty years in captivity.
Pitless vipers (subfamily Viperinae) of the Cerastes genus are the three species of Old World sidewinders. In the Sahara, two of them (C. cerastes and C. vipera) live. In the Middle East and Arabia, the third (C. gasperetti) is found. All are small (50 cm) and stout with large heads; above each eye, some individuals have a hornlike scale.
Their coloration is red, with darker spots on the back, resembling their environment's desert sands-shades of tan, pink, orange, or green. They hide under the sand or rocks throughout the day; they emerge at night to search for mice, birds and lizards. These sidewinders lay from 8 to 23 eggs rather than give birth to live young.
For their unusual locomotion process, which leaves a typical j-shaped track, sidewinders are noted. The body's loops are thrown obliquely around the sand so that at every moment only two points are in contact with the earth. This, owing to excessive contact with the desert sand, prevents the snake from overheating. While they are venomous, they are usually not deadly to humans when they bite.