Indeed some crop circles have been made by hoaxers with plywood and yarn. But, the unexplainable crop circles [some very large] infact could only be duplicated with a team of people working together throught many hours of the night. And, for a farmer not to see or anyother witnesses not able to see all these people doing it is amazing. So infact some are unexplainable while others are just vandalism to a farmers crop. In order for some of the more ornate ones to be created it had to be done by a large group of hoaxers outfitted with night vision, and possibly gps maps. But, heh I don't know. Just a thought.