Have you seen this? Know the answer?

Try to solve this one:

When asked this riddle, 80% of kindergarten kids
got the answer, compared to
17% of Stanford University seniors.
    What is greater than God,
    More evil than the devil,
    The poor have it,
    The rich need it,
    And if you eat it, you'll die?

ANS:  Mouse over the image 

Answer:  NOTHING