Every day, millions of people watch their pet reptiles run, dig, swim or climb up against the walls of their enclosure. Reptile keepers call this “glass surfing,” but among scientists, this conduct is typically considered to be a type of repetitive behaviour, akin to pacing in polar bears . Repetitive interactions with the barriers of a tank or cage might initially be endearing — because it seems like the reptile is eager to explore — but can quickly become distressing if a reptile simply does not stop . Many people feel helpless as they watch their beloved pet rub the scales on their nose off, causing ulcerations or deformities, or dig at the walls of an enclosure until streaks of blood are left behind. Why do they do this, and how can we stop them? Our lab examined the behaviour of one of the most popular pet reptiles around the world — the bearded dragon — and discovered some interesting similarities between repetitive behaviours in reptiles and mammals.…