Wallabies are getting stoned on Tasmania's opium poppy crops and hopping about in circles, authorties say.
Attorney-General Lara Giddings says wallabies have created crop circles of squashed poppies as they increasingly hop in to the fields eating the poppy heads.
That causes them to get high and run around in turns creating crop circles, she told a budget estimates hearing.
"The one interesting bit that I found recently in one of my briefs on the poppy industry was that we have a problem with wallabies entering poppy fields, getting as high as a kite and going around in circles," Ms Giddings is quouted in The Mercury newspaper as saying.
"Then they crash. We see crop circles in the poppy industry from wallabies that are high."
Tasmanian Alkaloids field operations manager Rick Rockliff said wildlife and livestock which ate the poppies were known to "act weird" - including deer and sheep in the state's highlands.
"There have been many stories about sheep that have eaten some of the poppies after harvesting and they all walk around in circles," Mr Rockliff told The Mercury.
Tasmania is the world's largest producer of legally grown opium for the pharmaceutical market.
About 500 farmers grow the crop supplying the market with about 50 percent of the world's raw material for morphine and related opiates.
Ms Giddings was answering questions about the security of Tasmania's poppy stocks, which are considered some of the safest in the world.