those darn farmers ;-)

A farmer got pulled over by a State Trooper for speeding. The trooper
started to lecture the farmer about his speeding, and in general began
to throw his weight around to try to make the farmer feel uncomfortable.
 
Finally, the trooper got around to writing out the ticket. As he was doing that, he kept swatting at some flies that were buzzing around his head. The farmer said, "Having some problem with circle flies there, are ya?"

The trooper stopped writing the ticket and said, "Well yeah, if that's
what they are. I've never heard of circle flies." So the farmer says,
"Well, circle flies are common on farms. See, they're called circle flies because they're almost always found circling around the back end of a horse." The trooper says, "Oh," and goes back to writing the ticket.

Then after a minute, he stops and says, "Are you trying to call me a
horse's ass?"

The farmer says, "Oh no, officer. I have too much respect for law
enforcement and police officers to even think about calling you a
horse's ass."

The trooper says, "Well it's a good thing," and goes back to writing the ticket. After a long pause, the farmer says,

"Hard to fool them flies, though."