Viral videos of distressed kangaroos bouncing around erratically have stirred up concern and sympathy across the internet. Despite claims that these kangaroos look “drunk,” it might be more accurate to say that these kangaroos are high. They’ve been eating DMT-laced grass for days, and if earlier research on what the plant does to sheep holds true for kangaroos, it’s also causing a slew of other weird and potentially fatal effects.

In June, The Guardian reported that the kangaroos are suffering from a condition called “phalaris staggers,” which happens when kangaroos — or pretty much any other animal — munches too much Phalaris aquatica, a grass that produces DMT naturally. DMT is a potent psychedelic substance sometimes referred to as the “spirit molecule.”

In addition to giving animals the staggers, the plant can turn kidneys green and cause a strange amount of “head nodding,” as the studies on sheep have shown. Sometimes, the kangaroos suddenly die from eating all that grass through a condition called “phalaris toxicity.”

While there is little research into how DMT interacts with kangaroo brains, there is a small body of literature showing how it interacts with sheep because farmers in Australia have been feeding it to their flocks for decades. A 2014 paper published in the Australia Journal of Toxins noted that eating phalaris not only caused “hyper-excitability,” “muscle tremors,” and “an ill-coordinated ‘proppy’ gait” but also caused the sheep’s kidneys to turn green and small amount of a “golden brown deposit” to manifest in their neurons.

No one really knows why Phalaris aquatica causes these strange effects in sheep, and researchers at the University of Melbourne are currently working on confirming whether the grass is really behind the weird behavior of their kangaroos. As of right now, evidence that the DMT inherent in the grass is the culprit comes from a 1967 study in which scientists injected DMT into the jugular veins of sheep, and waited to see whether their behavior mimicked that of sheep with “the staggers”:

“Each of the alkaloids passes quickly into the brain from the blood, and produces neurological signs within 13-16 seconds of injection into the jugular vein of sheep,” the researchers observed. “[It] produces behavioural hyperexcitability and anxiety, licking of the lips, salivation, wrinkling of the face, nodding of the head, chewing movements, flaring of the nostrils, twitching of the tail,… and localized spasms of muscles.”

This is an incredibly old study, but there have has been some more recent research that highlights DMT’s causal role here. The 2014 paper cites three other papers from 1973, 1979, and 1998 that describe how drought conditions contribute to the amount of alkaloids (the chemical class that DMT belongs to) produced by different types of phalaris plants. Specifically, in areas where soil cobalt (a mineral that protects against moisture loss in some plants) was low, the levels of alkaloids were very high:

A field of Phalaris aquatica Wikimedia

“Therefore, soil cobalt deficiency could reduce the plant’s drought tolerance causing enhanced alkaloid toxin production due to stress, thereby increasing the likelihood of incidence of phalaris toxicity in deficient soils,” the 2014 paper summarized.

The research on how DMT can potentially affect wildlife and livestock has been effectively been cornered by Australian researchers. When Inverse called sheep experts in 12 states, few had even heard of this condition — although one mentioned that lots of plants are toxic to animals, like rhododendrons. But when it comes to helping the staggering kangaroos, it seems like the Australians are on their own.