An old farmer was hauling a load of manure when he was stopped by a state trooper. "You were speeding," the cop said. "I'm going to have to give you a ticket."
"Ya gotta do what you've gotta do," the farmer said as he watched the trooper shoo away several flies.
"These flies are terrible," the trooper complained.
"Yep," the farmer agreed. "Them's circle flies."
"Circle flies?" asked the trooper, "Never heard of them. What are they?"
"Them's the flies that circle a horse's ass," answered the farmer, as he points to the cloud of insects. "Them are definitely circle flies."
"You wouldn't be calling me a horse's ass, would you?" The trooper angrily asked.
"Nope, I sure didn't, Officer," the farmer replied. "But you just can't fool them flies!"