During the Warring States period (475-221B.C.), Prince Mengchang of the State of Qi was fond of having various kinds of people as his hangers-on, the number of whom was said to have amounted to three thousand. Never refusing anyone who came to hime, he let the talented people do what they could and also offered food and lodging to the mediocre.
Once, followed by his hangers-on, Prince Mengchang was sent on a diplomatic mission to the State of Qin. Attempting to make him prime minister of the state of Qin, King Zhao of the State of Qin kept him from leaving. Not daring to offend the king, Prince Mengchang stay here. He is a person of royal lineage, and has feud and family back in the State of Qi, How could he serve the State of Qin heart and soul? The king thought it plausible, and changed his mind. He put Prince Mengchang and his hangers-on under house arrest, waiting to find an excuse to kill them. The king had an imperial concubine on whom he doted most, and he never refused her anything, Prince Mengchang sent a man to her for help. The concubine promised to help if she could have the unique white fox fur coat of the State of Qi as her reward. Prince Mengchang was troubled, for he had already given it to the king of the State of Oin as a gift when he arrived here. Just then, one of the hangers-on said, "I can manage to get it".
He left immediately .It turned out that this man was a skilled burglar who used to enter horses through the hole for dogs in the wall. He made an investigation first, and learned that the king was too fond of the fox fur coat to wear it and that the coat was kept in the choice storeroom in the palace. Eluding the patrol, he found his way easily in the moonlight into the storeroom and got the fur coat out. Seeing the coat, the concubine was extremely pleased; She tried every means to talk the king into giving up the idea of killing Prince Mengchang. The king also planned to give a farewell dinner to Prince Mengchang two days later before sending him back to the State of Qi.
But Prince Mengchang did not dare to wait two more days. Mounting the horses, he and his men sped stealthily eastward that very night. It was just midnight when they arrived at the Hangu Pass (in today"s Lingbao County in Henan Province, which was the east gate of the State of Qin). According to the laws of the State of Qin , the gate of the pass should not be opened until cocks crew in the morning. But how could they crow at midnight? They were very much worried when they heard a cock crowing. Immediately all the cocks inside and outside the pass followed the cock in crowing .It turned out that one other hanger-on could imitate the cocks crow very well, and the first crow was actually his imitation. The guards of the pass felt it very strange to have heard the cocks" crow before they could hardly have had enough sleep. Nevertheless, they had to open the gate of the pass and let them go.
At dawn, the king of the State of Qin learned that Prince Mengchang and his men had escaped. He immediately sent his troops to chase them. When the troops arrived, he immediately sent his troops to chase them. When the troops arrived at the Hangu Pass, they had gone for a long time. With the help of those people who knew small tricks such as crowing like a cock and snatching like a dog, Prince Mengchang finally got back to the State of Qi. This story appears in "The Life of Prince Mengchang" in the Historical Records written by Sima Qian. Later, the set phrase "crowing like a cock and snatching like a dog" is used to refer to small tricks or people who know small tricks.