Well, obviously people make crop circles, that's by far the simplest and most likely explanation. If you really wanted to make one, it wouldn't be that hard, and in fact, there have been crop circle contests where the winning circles looked just as perfect as supposedly alien ones people find in cornfields. As for the non-perfect ones, they're not reported as often because there's simply no reason to, at least not by believers, as they wouldn't bolster the case of insane people who think aliens make them. This whole business is ridiculous. Have you ever seen aliens in the process of making crop circles? No?