Of course they did - "Stone Age man took drugs, say scientists."

Stone Age man took drugs, say scientists - Telegraph:

"It has long been suspected that humans have an ancient history of drug use, but there has been a lack of proof to support the theory.

Now, however, researchers have found equipment used to prepare hallucinogenic drugs for sniffing, and dated them back to prehistoric South American tribes."

Psychedelics are why we believe in gods and have religion. And probably why we have speech and communication as well. But shhhhh! ...don't tell anyone.