Xiamen Yundang Lake adheres to the sustainable development of the ecological environment, utilizing the tidal effect of seawater to divert seawater into the lake. This not only purifies the lake, but also provides abundant food for egrets, appearing a beautiful scenes of egrets and big fish competing for small fish. On the turbulent sea surface, as soon as the egret caught a small fish, the fierce big fish rushed out of the water, opened its big mouth, and prepared to snatch the small fish. Under the rule of the jungle where the weak prey, who would the small fish belong to?