In ancient times, people not only knew that centipedes ate snakes, but also knew that snakes ate frogs and frogs ate centipedes. Guan Yinzi Shan Zhi, a Taoist work in the Southern Song Dynasty, said: "Snakes eat snakes, snakes eat frogs, and frogs eat mantis maggots and eat each other."
There is a similar description in Lu Dian's Ya Ya: "The maggot hits the snake. As the old saying goes, toads eat networms, networms eat snakes, and snakes eat toads. " The frog is replaced by toad here, but it still conforms to the actual situation of nature.