Crop Circles, Ice Circles, Dirt Circles, Mud and Snow Circles! Whatever your cereology passion is we've got some more info on the possible natural explanations, UFO or alien involvement and of course the human made versions.
Crop Circles. Through the last decade and into the 2000s many crop circles now have a high probability of being created by human 'artists' with neutral intentions. Those dating from the early 1990s and prior have a higher likely hood of being of simpler design and potentially better chances of being created by a yet to be identified source. Author and UFOlogist Noah Voss UFOwisconsin.com