Earthworms are rich in protein, and can be used as feed for livestock, poultry and aquaculture, which can increase the yield. Earthworms also occupy a certain position in pharmacology, and are common Chinese herbal medicines, which have the functions of relieving fever, spasmolysis, activating collaterals, relieving asthma, lowering blood pressure and diuresis.
Earthworms can secrete a special enzyme, which can decompose protein, fat and lignocellulose. Therefore, leaves, straws, livestock manure, domestic garbage, activated sludge, scraps from paper making and food industry can all become their food, and earthworms can eliminate environmental pollution to a certain extent.
Therefore, in recent years, many countries have established earthworm breeding factories, which are called environmental purification devices. Because earthworms can absorb trace metals such as mercury, lead and cadmium in soil, the accumulation of these metal elements in earthworms is 10 times of the external content. Therefore, some scientists believe that earthworms can be used as monitoring animals for soil heavy metal pollution.