Dr. Colin Andrews has researched crop circles for 17 years, employing private
detectives to track hoaxers. He believes that, whilst 80% of crop circles are
man-made, the other 20% are caused by
shifts in the Earth's magnetic field.
Self-proclaimed hoaxer John Lundberg said no-one would ever believe a
scientific explanation for crop circles because people want to believe it is
something more mysterious. "The public don't want it explained," he said.