Snake is an animal with a long, legless body covered by dry scales. To move about on land, a snake usually slides on its belly. Many snakes have such a flexible body that they can coil into a ball. The eyes of a snake are covered by clear scales instead of movable eyelids. As a result, its eyes are always open. Snakes have a narrow, forked tongue, which they repeatedly flick out. They use the tongue to bring odors to a special sense organ in the mouth. .
Snakes belong to a class (group) of animals called reptiles. Reptiles also include crocodiles, lizards, and turtles. Like other reptiles, snakes can maintain a fairly steady body temperature by behavioral means. For example, they raise their body temperature by lying in the sun or lower it by crawling into the shade. In contrast, mammals and birds have internal mechanisms that regulate their body temperature. .
Anaconda «AN uh KON duh », is the name of two kinds of large snakes found in tropical South America. Anacondas are also called water boas. One kind may grow as long as 30 feet (9 meters) or more. But all adult anacondas are more than 15 feet (4.6 meters) long. No other South American snake approaches this length. .
Anacondas have olive-green skin, often with many black rings or spots. These snakes live near water, often swimming in rivers. Anacondas bear live young. Their main foods are birds and small mammals. They kill their prey by wrapping their coils tightly around them to keep them from breathing. Only the largest anacondas ever attack large mammals. Like most snakes, they defend themselves from enemies by retreating or, if cornered, by biting. Their bite is not poisonous, but their many teeth can inflict deep wounds. The anaconda lives throughout tropical South America, east of the Andes, mainly in the Amazon and Orinoco basins, and in the Guianas. It extends to Trinidad.