Worms

A dad was trying to teach his kid about the evils of drinking. He put one worm in a glass of water and another worm in a glass of whiskey. The worm in the water survived, but the worm in the whiskey curled up and died almost immediately. “All right, kid,” the father began, “what does this little experiment prove to you about drinking?”
“Well,” the kid replied thoughtfully, “it proves that if a person drinks alcohol he probably won’t get worms.”