FARMER AND THREE PIGS
Once upon a time a farmer wanted to breed his 3 female pigs. He loaded the sows into the back of his pickup truck and took them to visit several boars at a nearby farm.
While the pigs were getting acquainted, the farmer asks the neighbor, "How will I know if my pigs are pregnant?"
"That's easy," said the neighbor, "They roll in the grass when it takes and they wallow in the mud when it doesn't take."
The next morning the farmer woke, looked out of the window and found his pigs wallowing in the mud. So he loaded them back in the truck and took them to see the boars.
The following morning the pigs were still wallowing in the mud. Undaunted the farmer once again loaded the pigs into the truck and took them back to the boars for the third time, hoping for some positive results.
The following morning the farmer was away from the farm. So he anxiously phoned his wife and asked "Are they rolling in the grass?"
She said "no".
He asked "are they wallowing in the mud?"
She said "no."
He asked "where are they?"
The wife replied, "They are out in the truck blowing on the horn."
Point: You get more of the behavior that you reward.