Poetry like a bird

Fish and shrimp in the pond are nowhere to be found, and birds have nothing to eat underground. What is the zodiac? The answer is not the zodiac, but the crab. Crab is a crustacean. It breathes through its gills. Its gills are very suitable for drawing water in a pond and absorbing dissolved oxygen in the water, just like fish. Besides, their bodies are covered with hard shells, just like shrimp. These are the reasons that lead to the disappearance of fish and shrimp in the pool. Birds looking for food underground does not mean that they eat food underground, but look for insects, seeds and other foods from the soil, and the hard shell of crabs can prevent them from being eaten by birds. So there are no fish and shrimp in the pond and no food under the birds. This is a description of crabs.