The Freshwater Crayfish is common in water bodies of the temperate latitudes and partially the southern stretches of the northern hemisphere. Its native range includes most parts of Europe, the basins of the Caspian Sea, the Black Sea and the Sea of Azov, rivers and lakes of Western Siberia. The crayfish lives in clean flowing water with sufficient content of oxygen and mineral salts. It makes burrows under snags or buries itself in silt or sand. They are a nocturnal creature. In summer, it lives in the shallows, in winter, it moves to deeper areas. It feeds mainly on plants, yet it preys on insects, worms and tadpoles. Often it eats carrion. The crayfish smells decaying frogs and fish from a long distance. The body of a crayfish, consisting of the cephalothorax and the jointed flat abdomen, is protected by a hard chitin shell. There is a sharp rostrum on the head segment with two long thin antennas on its sides. Its coloration may vary depending on water color, usually it is greenish brown or dark tawny. The front pair of legs bears the large chelae, that the crayfish uses for defense and attack. Large specimens reach a length of 20 cm.