One morning a rancher says to his wife, Amy: "The insemination man is coming over to impregnate one of our cows, so I drove a nail into the 2x4 just above where the cow's stall is in the barn. Please show him where the cow is when he gets here, OK?" Then the rancher leaves for town.
Later, the artificial insemination man knocks on the front door. "I came to inseminate the cow," he says. Amy takes him down to the barn, walks along the row of cows and, when Amy sees the nail, she says, "This is the one, right here.” Assuming he is dealing with an airhead blonde, the man asks, "Tell me, young lady, 'cause I'm dying to know, how would YOU know that this is the right cow to be bred?”
"That’s simple by the nail that's over its stall," she explains with confidence. Laughing rudely at her, the man says, "And WHAT, pray tell, is the nail for?” As she turns to walk away, she says sweetly over her shoulder, "I guess it's for you to hang your pants on."