Amazing crop circles

Some new ones in Brazil -- and a slide show of many of them from the past and present.  No one really knows how they are made--or who is making them....(and it ain't those old geezers Doug and Dave, one of whom died a few years back).  So many mysteries...so little time....

http://www.huffingtonpost.com/2013/11/20/two-brazil-crop-circles-form-on-same-day_n_4298725.html?hpweird=y