**2.1 Distribution of earthworms**

Earthworms occur all over the world, but are rare in areas under constant snow and ice, mountain ranges and areas almost entirely lacking in soil and vegetation (Edwards and Bohlen, 1996). Some species are widely distributed, which are called peregrine, whereas others, that are not able to spread successfully to other areas, are termed as endemic (Edwards and Lofty, 1972).
