The usual habitat of leeches are ponds, marshes, shallow lakes, backwaters of rivers with low flow rate – in a word, ponds, where the water warms up quite well, with a muddy and rocky bottom. Leeches, as you well know, in order to maintain its zhiznideyatelnosti feed exclusively on blood. They attach themselves to the frogs, snails, fish, waterfowl, but their favorite food – large blood of warm-blooded animals. In large medical encyclopedia published in 1982, reported that in the USSR there are two kinds of leeches: medical and Nile (horse). Horse leech usually lives in the Caucasus and Central Asia. It can be found in slowly flowing waters. If you drink unboiled water from these reservoirs can be swallowed small leech, it will be able to get into your mouth, stick to the vessels, and drink the blood of his victim. You’ll find most leeches where bathing cattle. Animals which have stuck leeches are able to carry them too far from the reservoirs. With the ability for a long time without water, leeches tolerate long journeys. During warmer months, fed leeches usually fall to the bottom of the pond in the mud and on sunny days lively float on the pond in search of new food. When the ponds dry up or freeze, leeches burrow deep into the ground, hibernate. To the extent that the water they return to normal life, most often occurs in the summer. That summer, medicinal leeches comes the most crucial period in their lives – during the breeding season. Mature individuals are able to break through the rather long and dry passages in the bottom of the reservoir, in the mud or in the ground, where they lay their cocoons. Cocoon resembles a leech in appearance silkworm cocoon. Under the spongy surface of the cocoon is gelled protein mass, and in it – the fertilized egg. Leech lays up to five pods, each of which can be up to 20-30 eggs. Development of the embryo usually does not last more than a month, leeches feed on buds protein mass contained in breast .As they mature, depending on the humidity of the first ambient temperature, young leeches succumbed cocoons and begin to live independently. Small young leeches easily tolerate hunger. Under natural conditions, they grow slowly for a long time and increase the mass of his tiny body, acts as bloodsucking do not happen too often. In the laboratory, the leech can live up to one and a half years without food intake. But if you feed them regularly, they do not give up food on a monthly basis.