Here's my version of a joke I heard (or received) about a farmer trying to outsmart some local teens. Enjoy...
There was this one farmer who, among other things, grew an annual crop of watermelons. For years he had great crops of watermelons, but then slowly he noticed that local teenagers were sneaking into the patch overnight and helping themselves. First to a few, then a few more, then dozens would go disappearing in the night.
Finally, the late night thievery got so bad the farmer couldn't take it anymore. He thought about what he could do to put an end to it without a lot of cost or work on his part. Finally it came to him...
With a wide smirk on his face he took an old piece of plywood from his barn, painted his message on it in big letters and hung it at the entrance to the watermelon patch. The sign read:
"THIEVES BEWARE! ONE of the WATERMELONS in this patch is POISONED!"
Happy with himself for coming up with such a plan, the old farmer walked back through the watermelon patch to this house.
The next morning, he got up and walked back out through the patch. Sure enough, not a single watermelon was missing. His smile spread and he was whistling to himself until he got to his sign.
There, next to his plywould sign was a cardboard one with a message in black marker: