The snakes or serpents are legless reptile, some of which have a venomous bite which they use to kill their prey before eating it. Other snakes kill their prey by constriction[?], for example strangulation.
Snakes are closely related to lizards, which share the order Squamata[?]. There are also several species of legless lizard[?] which superficially resemble snakes, but are not otherwise related to them.
Although they may be venomous and have a bad reputation, snakes do not not prey on humans. Most snakes will attack a human being only if startled or injured. If you look where you are walking and make plenty of noise, a snake will get out of your way rather than waiting for you to step on it. In many areas, most snakes are non-venomous or have venom that is not harmful to humans, and are Colubrid. Australia is an exception - most snakes in Australia are extremely venomous and should be given a very wide berth.
All snakes are carnivorous, eating small animals, birds or insects. Snakes do not chew their food. Many snakes have an ability to unhinge the joints in their jaws thus allowing them to open their mouths wide enough to swallow their prey whole, even if it is larger in diameter than the snake itself. After eating, snakes become torpid while the process of digestion takes place.
The skin is covered in scales. Most snakes use their scales to move, gripping surfaces. They shed their skin periodically. Detailed vision is limited, but does not prevent detection of movement. A subgroup of snakes called the pit vipers have infrared sensitve receptors in deep grooves between the nostril and eye which allow them to 'see' the heat radiated by animals. Hearing is restricted to the sensing of ground vibrations. A snake smells through its nose, and the tongue passes airborne particles to special organs in the mouth for examination. The left lung is very small or even absent.
The Snake is one of the 12-year cycle of animals which appear in the Chinese zodiac related to the Chinese calendar. It is thought that each animal in the Chinese zodiac is associated with certain personality traits.