Sidewinding is a type of locomotion unique to some snakes. They use it to move across loose or slippery ground like sand or mud. It is often used by the Saharan horned viper, "Cerastes cerastes", and the sidewinder rattlesnake, "Crotalus cerastes", to move across loose desert sands. It is also used by some snakes in Southeast Asia to move across tidal mud flats. Other snakes can be induced to sidewind on artificial smooth surfaces, with various degrees of success. Sidewinding is not the only way snakes can move on sand.