Aristotle didn't think so. He thought laughter was something that separates humans from the rest of the animal kingdom. But at Bowling Green State University in Ohio, psychobiologist Dr. Jaak Panksepp says he can make rats laugh. Human ears just can't hear it. It is crazy how in this video after he "tickles" the rat, it follows his hand like it is asking for more.
Radio Lab did a show on laughter, where I got the link to this video.