In ancient times, a man surnamed Dong in the State of Wei was interested in nothing but keeping cats.
He kept over one hundred cats in his home, which caught and ate all the rats in the house.
Later, with no rats left, the cats grew hungry and meowed constantly. Dong had to buy meat daily from the market to feed them.
Day after day, year after year, the cats multiplied. Accustomed to a daily diet of meat, they forgot that rats could be caught and eaten. They meowed when hungry and were promptly fed. Once full, they became happy, carefree, lazy, and sluggish, with nothing to do all day.
In the south of the city, one household was plagued by rats. The rodents ran amuck in swarms. Once, a rat fell into a jar. The master of the house hurried to Dong's home to borrow a cat.
The cat from the Dong family saw the rat in the jar: its pointed ears erect, pitch-black eyes staring, red whiskers shaking as it squeaked. The cat, unsure what this creature was, merely followed the rat's movements around the jar's mouth, not daring to enter.
Furious, the master pushed the cat into the jar. Panic-stricken, the cat howled loudly at the rat. After a while, the rat realized this cat had no other tricks and bit its foot. Terrified, the Dong family cat mustered all its strength, leaped out of the jar, and fled.