This storybook delves into the fascinating world of earthworms. Earthworms are introduced as invertebrates that migrated to the United States millions of years ago, as evidenced by fossils. It details the anatomy of these creatures, highlighting their segmented bodies, bristles known as setae, and the unique respiratory system that requires them to stay moist. The story further discusses earthworms' functional features, including their muscular structure for movement and multiple hearts to circulate blood. It explains that they possess a gizzard for grinding food despite lacking eyes or teeth and describes their reproductive process, resulting in small cocoons. The narrative emphasizes the vast diversity of earthworm species, with some growing as long as 22 feet.