Watermelons with Cyanide

A farmer in the country has a watermelon patch and upon
inspection he discovers that some of the local kids have been
helping themselves to a feast.


The farmer thinks of ways to discourage this profit eating
situation. So he puts up a sign that reads "WARNING: ONE OF
THESE WATERMELONS CONTAINS CYANIDE!"


The farmer returns a week later to discover that none of the
watermelons have been eaten, but finds another sign that reads,
"NOW THERE ARE TWO!"