The reasons why a cat moans in grievance are as follows: 1. When a female cat enters estrus, she will like to scream, especially at night, accompanied by twisting and rolling, raising her tail and buttocks; 2. The cat may be wronged or missing The owner is acting coquettishly and showing kindness to the owner; 3. If the cat meows and shows no energy, the owner should observe to see if it is sick or unwell.