Snakes are elongated legless cold-blooded carnivorous reptiles of the suborder Serpentes, that can be distinguished from legless lizards by their lack of eyelids and external ears.
All snakes are strictly carnivorous, eating small animals including lizards, other snakes, small mammals, birds, eggs, fish, snails or insects. Because snakes cannot bite or tear their food to pieces, a snake must swallow its prey whole. The body size of a snake has a major influence on its eating habits. Smaller snakes eat smaller prey. Juvenile pythons might start out feeding on lizards or mice and graduate to small deer or antelope as an adult, for example.
Most species are non-venomous and those that have venom use it primarily to kill and subdue prey rather than for self-defense. Some possess venom potent enough to cause painful injury or death to humans. Non-venomous snakes either swallow prey alive or kill by constriction.
Snakes do not ordinarily prey on humans and most will not attack humans unless the snake is startled or injured, preferring instead to avoid contact. With the exception of large constrictors, non-venomous snakes are not a threat to humans. The bite of non-venomous snakes is usually harmless because their teeth are designed for grabbing and holding, rather than tearing or inflicting a deep puncture wound. Although the possibility of an infection and tissue damage is present in the bite of a non-venomous snake, venomous snakes present far greater hazard to humans.
Depending on the snake they usually are hidden in tall grasses or small tight spaces like under parts of rocks and some even live in trees.