Because most of the Forbidden City is a wooden building, it has suffered from rats, so it is memorable to have the habit of keeping cats and controlling rats in the palace.

There was a tradition of keeping cats in the Forbidden City in the Ming Dynasty. These cats are kept and managed by special people. They play and walk in the Forbidden City during the day and patrol to catch mice at night. Most of the buildings in the Forbidden City are made of wood. They used to be troubled by mice, but now they are well preserved. This group of "cat security guards" have made great contributions. In ancient times, there was a special place for cats in the Forbidden City. Most of these cats are concubines' pets. These cats are now in the Forbidden City. They are frequent visitors to the Forbidden City. Some tourists even gave these cats their own names. They are not afraid of people, and some kind people often come here to feed. After eating the food fed by people, they will destroy the mice in the Forbidden City by their own skills. In addition, they will shuttle around the Forbidden City at night, and some lawless elements will be intimidated by these stray cats because of their guilty conscience. Because stray cats have played a great role in the Forbidden City, people affectionately call these stray cats security cats.