From bonobos and rats to tickling robots, research is finally cracking the secrets of why we're ticklish, and what that reveals about our brains In a grey-walled room in the Dutch city of Nijmegen, a strange activity is underfoot. Wearing a cap covered in sensors and positioning themselves into a chair, a person places their bare feet over two holes in a platform. Beneath this lies a robot, which uses a metal probe to begin to tickle their soles. Here, at Radboud University's Touch and Tickle lab, volunteers are being mercilessly tickled in the name of science. "We can manipulate how strong the stimulation is, how fast and where it is going to be applied on your foot," says Konstantina Kilteni, who runs the lab, of the robot tickling experiment.