Australian farmers are dealing with a nightmare scenario: the rapid spread of a rare plant that’s causing sheep that eat it to act “drunk” and bash their own heads open.

“We counted 800 missing wethers (sheep) at shearing time,” farmer Louise Knight told the Sydney Morning Herald.

The sheep are eating darling pea, an endangered plant that’s normally rare in New South Wales, Australia, but which has spread rapidly after a massive brushfire cleared a broad swath of Warrumbungle National park and nearby farms.

(Image source: WHAT)

Darling pea, the rare Australian plant that’s spreading rapidly and intoxicating sheep that eat it. (Image source: screengrab via Landline ABC)

According to local veterinarian Bob McKinnon, sheep act “drunk” when they eat the plant.

“They lose weight to start with and then get staggery, the progression gets worse, they get unco-ordinated and depressed, they don’t know where their feet are and they become recumbent and die that way,” McKinnon told the Sydney Morning Herald.

(Image source: WHAT)

(Image source: screengrab via Landline ABC)

For farmers, the darling pea bloom is tragic.

“They just go to a post and bang their head on it till they crack their heads open,” said Knight, who runs a farm in central New South Wales with her husband Stephen. “It’s like dealing with a thousand heroin addicts.”

Follow Zach Noble (@thezachnoble) on Twitter