The team created mathematical models to account for the tail motion in three dimensions, and they built a robot dubbed Tailbot to figure it out. Tailbot was basically a remote-controlled car with an aluminum rod at its rear end. The team launched Tailbot off a ramp, inclined at the same angle as the lizards' vault, and kept the tail rigid. Tailbot plunged down nose-first. Then they used a tiny gyroscope as a sensor to provide Tailbot a sense of its own direction, and programmed the car to swing its aluminum tail in response. They launched it again, the tail swung upward, and Tailbot righted itself, maintaining a nearly constant body angle, the researchers report.