Manufacturing revitalized land: Of course the ecology of soil relies on many types of creatures, but the life of an earthworm can be ten years long. Compared to ants, millipedes, and the larvae of many insects, you could say that they are the "backbone" of the soil.
當然，土壤生態的改良，依賴的是許多族群，但蚯蚓壽命可以長到十年，和螞蟻、馬陸、許多昆蟲的幼蟲相比，可說是土壤中的大型無脊椎動物，也是初級分解者。