All species of snakes are carnivores, or meat eaters. Most snakes eat rats and birds, but some of the larger species can eat deer and other larger animals. Small snakes eat invertebrates, such as insects.
Another word for carnivorous is "zoophagous." "Zoo" means animal, and "phagous" means to eat.
Snakes kill their prey by biting and injecting venom or by squeezing prey to death with their strong, coiling, muscular bodies. Snakes that do not have venom and do not constrict simply grab prey with their mouths and swallow it. Many species also consume eggs.
Snakes eat much less than mammals because they are cold-blooded. A snake requires only about 10 percent the calories that a mammal of similar size needs.