Answer: Play Ping-Pong
B.F. Skinner was a highly influential 20th-century psychologist who founded the Radical Behaviorism school of psychological inquiry. He was singularly focused not on understanding the human mind as the psychologists that preceded him were, but in understanding how the environmental factors around us gave rise to our actions—a process he called operant conditioning.
He studied animals extensively over his career and used them as models to study operant conditioning wherein he could take even the smallest tasks, and through careful reinforcement, string them together so that the animal would perform them. Although his experiments were always serious scientific inquiries, Skinner was never against injecting a bit of levity into his work.
One of the more notable examples of this was his 1950 experiment wherein he taught pigeons to play what looked a whole lot like a game of ping-pong. The birds were trained, through his conditioning techniques, to want to knock the ball past the other bird because, in doing so, they would unlock the feeding box on their side of the cage and be rewarded.