The circles have many different formations. Most common are single circles, but sets of five are also found. None, however, are ever exactly alike. The only common denominator is that the corn or wheat crop is flattened but never damaged. Rather, the crop is swirled down to the ground.
Some people think that tricksters have selected isolated fields and mashed down the crop.
As Delgado and Andrews have shown, however, the circles are flattened in a swirl and have different layers within the overall pattern. No footsteps are found. A more plausible theory is that the circles are caused by a natural phenomenon known as a vortex, or whirlwind. Others believe that strong electromagnetic fields, deep in the earth may account for them. Either theory would help to explain why no two circles are the same, since wind currents and electromagnetic fields vary.