From The Huffington Post: Crop Circles Created By Wallabies 'Stoned' On Opium, Australian Officials Say
Filthy wallabies, indeed.
This article explains how the critters of the outback, namely the cute and cuddly wallaby, are ingesting the crops of local legal opium fields, getting "high as a kite" (this is put in quotes in the article, too, apparently a direct quote from Australian officials), and stumbling around the fields creating crop circles. Responsible for 50% of the legal opium production world wide, Australian poppy fields produce the primary ingredient in pharmaceutical drugs like morphine. Not to be confused with all the illegal poppy fields which are used to produce the world's supply of heroin and opium, over 90% of which are guarded and maintained by American troops in Afghanistan. Luckily there are no wallabies in Afghanistan, or they'd likely be riddled with machine-gun fire for tampering with the harvest.
Of course, this conclusion does little to explain many instances of crop circles world-wide where wallabies are not native to the area. The article also fails to provide any pictures of the critters' work. I for one would be quite interested to see how precise a stoned wallabies' crop circle would be. Reminds me of the experiment in which scientists fed various substances to spiders to observe how the intoxicants would effect the spider's prowess at building webs.
Either way, sounds like the wallabies know how to live it up in The Outback.