Crop Circle, Alien or Human ?

Another strange phenomenon in the world are increasingly adding a stack of phenomena-phenomena that are difficult to be solved by common sense humans even though scientists, namely Crop circle.

Crop Circle is a mysterious natural phenomenon which is now most often in jumpai.Sudah nearly 350 years since the first appearance in England in 1647, until now there has been no definitive answer to how they are formed.
Crop circle is a form of circles and other shapes such as geometry (size and plumpness of the range), even some that are commonly encountered form the image of living creatures such as scorpions, sunflowers, bees, agriculture dll.diladang khususunya wheat. In the UK, Canada, America, Australia, Japan and Indonesia, many found the phenomenon of crop circles. So what creatures like less work to make all of this? Alien or Human ?.