Telset, crop circles have been explained for more than 10 years, they are made by creative individuals (mostly university students) who have been filmed using night vision technology applying their craft.
There is no secret to crop circles they are made by hoaxsters.
I saw crop circles from the train when travelling in Sussex in the 1950's, I don't believe in visits from Extra thingys and they certainly weren't made by hoaxers in that era. I can't explain them.
I believe crop circles are made by a higher intelligence than university students namely a chimpanzee
Davidicus, you present a very compelling argument, however university students have been filmed creating these crop circles which is difficult to deny.