Response+Christine+K

To answer your question Bobby, I think Napoleon probably did it our of desire for power. He had power over the Animal Farm and did not want to lose that power to humans, similar to how Stalin did not want to lose his power to foreign countries who oppose Communism, such as America. That's probably why Napoleon wants the wind mill to be finished, so that the Animal Farm will get stronger and so that the humans will not have a chance to take back the farm.