The answer to this riddle is: mussels
The complete answer should be: it is difficult to fly with two wings, to make both clothes and houses, and it is better to teach the great waters to rush into the sea than to let the sun dry the houses. The two shells of the clam refer to the wings, and is both the clothes of the clam and the house of the clam. The clam is an aquatic animal, afraid of water and drought, so it is better to teach the big water rushing to the sea, not to call the sun drying house.