Giving ecstasy to octopuses for some reason

"I have to admit that it was totally trial and error. Honestly, I just didn't think this was going to work, so we started out at super high doses," she said.

Oh yes, very sensible.

"But the animals went through this hyper-vigilance where they were perched at the top of the tank like a hawk trying to watch a mouse or something." Surprised by the octopuses' sensitivity to the drug, the researchers scaled back the dose. "When we gave them the dose that you'd give a human, but adjusted for body weight, they started acting just like you'd expect a human to," Dr Dolen said.

Without ecstasy, test octopuses spent significantly more time in the chamber with the object. But with ecstasy, they became more social, preferring the chamber with the other octopus in it.

And the nature of the interactions between octopuses changed too. Before a dose of ecstasy, social interactions were "limited, usually to one extended arm", the scientists wrote in the paper. "After MDMA treatment, social interactions were characterised by extensive ventral surface contact, which appeared to be exploratory rather than aggressive in nature," they said.

http://www.abc.net.au/news/science/2018-09-21/octopus-ecstasy-mdma-social-behaviour/10280706