England has approximately 25 different species of earthworm. The most common of these is called the Common earthworm. However, there are over 1,800 earthworms in the world with most of them belonging to the Lumbrucus family, like the Common Earthworm. Earthworms are generally worms that burrow in soil, especially soil that is damp. They generally require damp soil because their slimy bodies need to be moist to enable them to breathe. Like amphibians they breathe through their skins. Our earthworms are not particularly large in size and rarely reach more than eight centimetres in length, although the Common Earthworm can be as long as thirty centimetres. However, earthworms are very numerous indeed. Charles Darwin estimated that each acre of land in England contained up to 50,000 earthworms. Darwin brought to our attention the tremendous value of earthworms as aerators and fertilisers of soil. In the course of one year, more than 15 tonnes of soil per acre may be brought to the surface by these little ‘cultivators’. Earthworms are often called nature’s ploughmen. Common Earthworms feed on decaying plant matter which they bring below from the surface at night to digest at their leisure and as they make their way to the surface they bring soil and digested matter. This turning over of the soil keeps the soil ‘healthy’ which often makes many farmers and gardeners happy.