Why hasn't anyone ever seen a person making a crop circle?

By the end of the 1980s, crop circles were very famous.

He funded a study about crop circles in the late 1990s.

In 1990, many more crop circles were reported, with some of the most beautiful shapes.

Many others have demonstrated how complex crop circles can be created.

After their announcement, the two men demonstrated making a crop circle.

Are they a distinctly American version of the crop circles?

By the 1990s, crop circles had become something of a tourist attraction.

Rockefeller also became interested in spiritual research and crop circles.

Methods of creating a crop circle are now well documented on the Internet.