Australian authorities have discovered what is responsible for the mysterious crop circles regularly appearing in Tasmanian poppy fields.

The cause of the crop circles is the wallaby, a small marsupial. The animal gets high from ingesting poppy plants and is then compelled to run around, creating crop circles. Likewise, cows and sheep that find their way into poppy fields also run in circles after eating the plant.

The island is the world's largest producer of medical opium. Used in the pharmaceutical industry, opium is the basis for morphine and other prescription opiates.

photo by Timmy Toucan/flickr