>Crop circles are easily explained

Not.

• they are created almost instantly when two blobs of light hover over them, according to witnesses and videos. Or "overnight", according to farmers. "This morning, it was there." Fake crop circles take a long time to lay out and flatten.
• the way the plants are bended is impossible to reproduce. The stem is not damaged, just bent. Fake ones squish and break the stems.
• there is always some residual magnetism in the area. Fake crop circles don't have that.
• crops grow better later on in the area where the crop circle happened.
• some of the geometric designs are incredibly complex mathematically. Pranksters use much simpler designs.

Interestingly, when newspapers and "scientists" get wind of a crop circle and decide reluctantly to talk about it, they always refer to the known crop circle pranks and omit all useful details.