The science teacher put four worms in four separate jars, the first in a jar of alcohol, the second in a jar of cigarette smoke, the third in a jar of sperm, and the fourth in a jar of soil. The next day, the first, second and third worms were dead, but the fourth worm lived happily in the soil. The science teacher asked, "Now, class, what can you learn from this experiment?" Little Johnny raised his hand. "As long as you smoke and drink and have sex, you'll never have worms!"