The reason why a cat keeps chewing without food in its mouth may be: the cat is swallowing its own hair, the cat’s gums are inflamed, the cat wants to spit out hair balls, or the cat has eaten the wrong food and wants to spit it out; the above reasons It is not a big problem if the cat keeps chewing on the air. If it is accompanied by symptoms such as loss of appetite and lack of energy, the owner needs further observation.