Circle Flies

It's the middle of summer and a Highway Patrolman pulls over a motorist for speeding. While he's writing the ticket, flies keep buzzing around his head, annoying him considerably.

"Circle flies sure are bad this year, aren't they?" says the motorist.

"Yeah," says the patrolman, "if that's what these are, you're sure right. But I've never heard of a circle fly before. What's that?"

"Well," the motorist responds, "circle flies are a species of fly that are particularly partial to horses. Specifically, they tend to circle around a horse's rear end. That's why they call 'em circle flies."

The patrolman, catching the implication, replies, "You don't say. Well, that's very interesting. But it strikes me that you might be trying to call me a horse's ass. You wouldn't be making that kind of implication about an officer of the law, would you?"

"Oh, no sir!" responds the motorist. "No, sir, not at all. I have the utmost respect for law enforcement officers, and would never dream of implying that one of them was a horse's ass. No, sir, I'm terribly sorry if that's how it sounded."

"Yeah, I didn't think so," replied the patrolman.

"Yeah," the motorist continued, "but there's just no fooling those circle flies, is there?"

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Another version

Horse Flies

On a hot summer's day a country boy is pulling a wagon load of manure down a country two lane road in rural Alabama. The local sheriff (Bubba) pulls him over and starts to write him a citation. As the sheriff is standing next to the old boy's pickup some of the flies accompanying the manure wagon start to buzz him. He swats at the flies and cusses them "damn flies." The country boy speaks up and says "Them's circle flies... we calls 'em that cause back home on the farm they's always circling the horses ass."

"Boy, are you calling me a horse's ass?" says the angered Bubba.

The country boy replied "No sir, but you can't fool them flies."