What Happens When You Tickle A Gorilla?
He laughs!
By tickling young gorillas, chimpanzees, bonobos, and orangutans, researchers say they learned that all great apes laugh.
Their findings suggest we inherited our own ability to laugh from the last common ancestor from which humans and great apes evolved, which lived 10 to 16 million years ago.
via Apes Laugh, Tickle Study Finds.
Click through to hear sounds of ape laughter; I liked the chimp one the best.