Crop circles are designs in crop fields. Most of these are made overnight but not all of the time. The first ones were discovered in England. 90% of all crop circles are found in England. They appeared first in the 1970's.
Crop circles are usually found in trees, ice and of course crops. The ones that were found around the 1970's were fairly simple. Some people have made it a hobby to go out at night and make crop circles these people are usualy found in England.
When crop circles are made ( not made by humans) witnesses claim they heard a high frequency sound. When crop circles arn;t human made there stems are charred and the node is bent and expanded.
After World War II the sightings and complexity increased. This may be because of the more planes flying over-head. They are usually found around Southern England where there is a large amount of crop fields.
It is simple to tell if crop circles are human made or not. If they are the stems are broken...If there not the stems are bent. Are these made by extra terrestrials or a natural cause?
