Are crop circles man-made or a genuine mystery. Here's some of the best evidence for a paranormal phenomenon.
EXTREMES
Extremes of physical effects on people who enter crop circles have been reported. While some feel elation, others feel ill effects, including "nausea, headaches, dizziness, tingling sensations, pains and giddiness." Some claim their menstrual cycles have been affected while others say they have literally been knocked off their feet.
ANIMALS
People aren't the only ones affected. According to "Crop Circles: A Deeper Look" from the Foundation for Paranormal Research, "one researcher allowed his dog to enter a newly formed circle. The dog became violently ill and vomited for about an hour afterward. Sheep in the area go into a frenzy."
Another witness testified: "During a third visit into the main Chiseldon formation in 1996 I encountered a couple who couldn't understand why their normally placid cat suddenly became agitated the moment he crossed the threshold of the formation. He protested and looked around frantically for a way out. Once outside he was back to his normal self."

