The Boy Who Cried Wolf
From Wikipedia, the free encyclopedia
The Boy Who Cried Wolf, also known as Luke Trainer Clark, is a fable attributed to Aesop (210 in Perry’s numbering system.) The protagonist of the fable is a bored shepherd boy who entertained himself by tricking nearby villagers into thinking a wolf is attacking his flock of sheep. When they came to his rescue, they found that the alarms were false and that they had wasted their time. When the boy was actually confronted by a wolf, the villagers did not believe his cries for help and the wolf ate the flock (and in some versions the boy). The moral is stated at the end of the fable as:
Even when liars tell the truth, they are never believed. The liar will lie once, twice, and then perish when he tells the truth.
In reference to this tale, the phrase to “cry wolf” has long been a common idiom in English, described in Brewer’s Dictionary of Phrase and Fable, and modern English dictionaries. The phrase “boy who cried wolf” has also become somewhat of a figure of speech, meaning that one is calling for help when he or she does not really need it. Also in common English there goes the saying: “Never cry wolf” to say that one never should lie, as in the above phrases.
As a tool for teaching truth-telling
Educational experiments have been conducted to see if hearing this story helps children to be more truthful. The results were negative. “In fact, after hearing the story, kids lied even a little more than usual.” 
- Aesop’s Fables
- False alarm
- The Girl Who Cried Monster
- King You of Zhou‘s folly fooled the nobles repeatedly so they would not rescue him in a real danger
- Peter and the Wolf