Fig. 4. Images of a jump by Ulopa viewed from the side. The images at the times indicated are arranged in two columns with the bottom left hand corner providing a constant reference point in this and in Figs 5, 6. The first movements of the hind legs (arrow) began 1.2 ms before take-off. The front and middle legs (arrows) lost contact with the ground before take-off. After take-off the body began to rotate backwards about its longitudinal axis. Images were captured at 5000 s^–1 and with an exposure time of 0.05 ms.