A farmer had five female pigs and, as times were tough, he had determined to take them to the county fair and sell them. While at the fair, he met another farmer who owned five male pigs. After talking a bit, they decided to mate the pigs and split everything 50/50.
Now, the farmers lived sixty miles away from one another, so they agreed to drive thirty miles each and meet at a field in which to mate their pigs. The first morning, the farmer with the female pigs got up at 5 AM, loaded the pigs into the family station wagon, which was the only vehicle he had, and drove the thirty miles. While the pigs were mating, he asked the other farmer,
"How will I know if they are pregnant?"
The other farmer replied,
"If they're in the grass grazing in the morning, then they're pregnant..... if they're in the mud, then they're not." The next morning they were in the mud, so he hosed them off, called the other farmer, loaded them again into the family station wagon and proceeded to try again. The following morning, in the mud again!! And the next morning, MUD again! This continued all week until the farmer was so tired that he couldn't get out of bed. He called to his wife,
"Honey, please go outside and tell me if the pigs are in the mud or in the field grazing." The wife walked outside to see and then came back and said, "Neither, they're in the station wagon and one of them is honking the horn."