Ducks' scam

During the Shunzhi period of the Qing Dynasty, Zheng Chenggong led his troops to fight against the Qing Dynasty along the coast of southern Fujian but was accidentally trapped in Haicheng City by 50,000 officers and soldiers led by Qing general Gushan Jinli. A few months later, the food in the city was about to run out, and Zheng Chenggong was very anxious.
　　
　　 One day, when Zheng Chenggong was patrolling, a soldier ran carrying two ducks and said: "This is a little bit of your heart, please accept it!"
　　
　　 Zheng Chenggong asked sharply, "How come there are ducks now? Where did they steal it?"
　　
　　 The soldier hurriedly replied: "It was not stolen, but it was caught in the trench."
　　
　　 Zheng Chenggong was a little skeptical and went to look at the trench with the soldiers. Sure enough, with the flood of river water, seven or eight ducks were caught in a while.
　　
　　 Everyone thought it was safe to eat ducks, but Zheng Chenggong said, "You can't kill a duck." Not only that, but he also asked the soldiers to feed the ducks with rice bran and send them out of the city when the tide was low.
　　
　　 Zheng Chenggong saw that everyone was puzzled, and explained: "The Qing army wanted to trap us in the city. If we couldn't find out the truth, we used ducks as spies. If we eat the ducks, we are telling the enemy that the city will run out of ammunition and food."
　　
　　 Gushan Jinli outside the city was watching the movement. Hearing that his men had caught the duck, he hurried to pick up a sharp knife and cut open the duck belly. It turned out that it was all rice bran. He killed a few more one after another, still the same! Gushan Jinli was dumbfounded and could only change the deployment and give up the siege.
　　
　　 There is no free lunch in the world. Don’t take advantage of the benefits that come easily. You need to be careful when it is profitable.