Here’s a classic riddle that often catches people off guard: What has four wheels and flies?
The answer: A garbage truck!
At first, the word flies makes you imagine something that moves through the air. But in this riddle, flies refers to the insects commonly found around rubbish. A garbage truck has wheels and may attract flies when collecting waste.
Why the riddle is clever
The trick is a word with two different meanings. “Flies” can be a verb describing flight, or a plural noun referring to insects. Your brain naturally chooses the first meaning, which makes the answer unexpectedly funny.
Not every garbage truck has exactly four wheels, of course. The joke uses a simplified image of a wheeled vehicle to set up its wordplay.
Try the riddle on a friend
Ask the question without emphasizing either meaning of “flies.” See whether they think of an unusual flying machine or an ordinary object with insects nearby. Once they hear “garbage truck,” the double meaning clicks into place.
