Crop circles on wheat fields in rural Perquimans County, N.C., in 1997. (DREW WILSON/AP)

Now, Australian farmers and an American scientist say they’ve found the answer. The only problem? Those answers are not the same. Or even close.

Australian farmers told world news site Global­Post that it’s all the handiwork of wallabies. And not just wallabies, but stoned wallabies, who ingest too many poppy plants and then hop around in circles high as kites. Before you laugh, the theory has been presented as a viable explanation for crop circles before.

But physicist Richard Taylor of the Materials Science Institute at the University of Oregon has a different idea. He says high-tech techniques such as GPS, lasers and microwaves are behind the flattened patterns of crops.

So who’s right?

Why it’s wallabies

At a state parliamentary hearing on the security of poppy crops in Tasmania, State Attorney General Lara Giddings said she was sure it was the marsupials.

“We have a problem with wallabies entering poppy fields, getting as high as a kite and going around in circles. Then they crash,” she said. “We see crop circles in the poppy industry from wallabies that are high.”

Tasmanian poppy farmer Rick Rockliff said that sheep may also be at fault. He said he saw walking around in circles in the fields after swallowing poppy. And many other farmers backed up Giddings and Rockliff.

Why it’s science

The wallabies don’t explain why crop circles have become more complex over time, some of them featuring up to 2,000 different shapes.

Taylor thinks artists have always been responsible, using rope and planks and wood in earlier times, and now using GPS, lasers and microwaves to flatten the crops. He calls crop circles one of the “most science-oriented art movements in history.”

One research team says they can reproduce the intricate designs on some crops using a handheld magnetron found in microwaves and a 12-volt battery.

Why it might be neither

If you believe the legends of old, crop circles are actually the handiwork of UFOs, or aliens. You decide.