Found at KA-CHING!:
An exchange student explained that he had been shot while fighting communists in his native country. They wanted to install a communist government. In the midst of his story he asked “Do you know how to catch wild pigs?” He explained that this was not a joke.
Put corn on the ground in the woods. The pigs will come every day to eat the free corn. When they get used to that, put a fence along one side of the area. When they get used to the fence, they will resume eating the corn. Then, put up another side of the fence. They will get used to that and resume eating.
Continue until you have all four sides of the fence with an open gate. The pigs will soon come through the gate to eat. Slam the gate on them, and catch the whole herd.
Suddenly, the wild pigs have lost their freedom. They will run around and around, but they are caught. Soon, they will go back to eating the free corn. They are used to it and have forgotten how to forage for themselves, so they accept their captivity.