All known snakes are carnivorous animals, there are predators. They feed on a variety of vertebrates and invertebrates, worms and mollusks to fish, birds, amphibians, rodents, and even small ungulates. The vast majority of snakes hunt for live prey.
Snakes do not chew the prey and swallow it, as if pulling her up his body. So the snake hunt only animals of this size are able to swallow whole. Way of hunting snakes depends on poisonous or not.
Just some poisonous snakes actively hunt or search for food. Steppe Viper steals locust and fast roll tries to grab her. 'The Copperhead snake, Echis creep in the burrows of rodents and eat their inhabitants, though they often hunt from ambush.
Non-poisonous snakes strangle their prey, or capturing and holding, swallow it. For example, snakes swallow prey (fish, amphibians, small mammals) live, not Wortley. Slender snake kills the victim, squeezing jaws and pressing the body to the ground. As Boas and pythons kill prey, squeezing strongly in the rings of his body. Coiled against around the body of the victim, they expect, when the animal will make the exhale, and then squeeze a little more, so until then, until she suffocated.