One of the great joys of science is the thrill of new discoveries. And one of the “truths” that most of us grew up with was the idea that only humans (and and maybe the occasional closely-related primate) use tools. Over time, we have found numerous examples of animals using tools (not to mention cooperating as opposed to competing) that have stretched our understanding.
So it may or may not come as a surprise that humans have been observing animals self-medicating for thousands of years, literally.
Animals self-medicate with plants − behavior people have observed and emulated for millennia
https://theconversation.com/animals-self-medicate-with-plants-behavior-people-have-observed-and-emulated-for-millennia-229768