Earthworms are invertebrates that belong to the phylum Annelida. They are found in almost all terrestrial ecosystems and play an essential role in maintaining soil health. Earthworms have a cylindrical body that is segmented, and they move by contracting and expanding their muscles. They have no lungs and breathe through their skin, which must remain moist. Earthworms are important decomposers and are instrumental in breaking down dead organic matter and recycling nutrients back into the soil. They are also a food source for many animals, including birds and small mammals.
