Chou explains that the goshawk uses its sharp beak and wolves, tigers, and panthers their razor claws to capture small animals. They maintain their existence by using the lives of others to nourish their own, which gives their lives a ruthless character. The earthworm, on the other hand, has neither beak nor claw and instead "eats the fertile soil and drinks the nether springs."
周公進一步解釋，像蒼鷹以尖鉤或像豺狼虎豹以利爪等捕食小動物，生存方式是以別人的生命餵養自己的生命，生活本質很殘忍；而小蚯蚓沒有鉤爪，僅以「上食膏壤，下飲黃泉」的方式過活。