Many snakes constrict prey to kill it before swallowing it.
Constriction involves wrapping loops of the body around a prey animal to restrain it so that it cannot escape or injure the snake, and to kill it before ingestion. Constriction was probably a key innovation in the evolution of snakes and was associated with the diversification of snakes. Snakes constrict many different kinds of prey. Some snakes constrict lizards and other snakes, but most snakes use constriction to kill mammals from mice to antelopes. The postures of constriction vary among snakes.