Apparently, the phenomenon is not species-specific. Some farmers have reported that crop circles were also made by stoned sheep and deer.
Australia grows about half of the world's legal medicinal opium poppies. Farmers may have to put up fences to keep out the hungry marsupials!
Implications - The featured video shows you what these flowers and pods that the wallabies eat look like. The video calls then "Tasmanian flowers," and they are actually quite pretty. They are a purplish pink mixed with white. Photo Credit: wizbangpop