Numerous crop circles have had orb type UFO sightings associated with them and even military helicopters have been seen to chase these orbs across the fields and the orbs behave as if controlled by an intelligence unknown to us or the military.
Almost as if the were a drone type of craft that behaves as well as moves with purpose. They have usually appeared just after a pattern has formed in a field in the early morning. In some cases they have also appeared during the middle of the day or later.
One thing is certain they have never been seen without a crop circle being nearby.