First logical question : Why the H*ll alien do that for?
In 1991, more than a decade after the phenomena began, two men, Doug Bower and Dave Chorley, revealed that they had been making crop circles in England since 1978 using planks, rope, hats and wire as their only tools. Many other people around the world are also openly making crop circles. Although the commonly accepted view today is that crop circles are a man-made phenomenon, paranormal explanations, often including UFOs, are still popular.In paranormal circles the study of the crop circle phenomena is called Cerealogy. Cerealogists commonly refer to these designs as agriglyphs or landscape art.
Crop circles are found in fields, over tree-tops, and in ice and snow. They are mostly often found in wheat or corn fields, but have also been found in oat, rape (canola), and barley. They are a world wide phenomena, highlighted in England.
No one knows how far back in history they go. Allegedly, the earliest recorded crop circle is depicted in this 1647 woodcut called the Mowing-Devil.