WALLABIES are getting stoned on Tasmania's opium poppy crops and hopping about in circles, authorities 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 quoted in The Mercury newspaper as saying.

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.

Tasmania is the world's largest producer of legally grown opium for the pharmaceutical market.

A wallaby.