 Dr. Masserman had 16 cats whom he trained to go to a box for food. Then after a while, he trained them to press a little red button and the box would open. And after a while, they learned that. And then he put an electrical charge on the red button so that whenever the cat's paw went down on the red button, he got a shock and he didn't want to go near the food. Dr. Masserman then spiked the milk.