Why cats meow so much at night:
1. When a cat is in heat, it will be restless and howl in order to attract a mate. You can take your cat to be spayed or neutered after the heat cycle is over.
2. Cats are nocturnal animals and usually become active at night, meowing and moving around the house. You can play with them more during the day to expend their energy, so they will rest quietly at night. 
3. Cats will also meow when they are unwell. Owners should check if the cat is sick and take it to the vet for examination and treatment in time.
4. When a cat is hungry, it will keep meowing to remind its owner to feed it. Usually, the owner can prepare food and water for it before going to bed.
5. When a cat is nervous or scared, it will keep meowing. The owner should soothe it in time to gradually relieve the tension.
