The housefly owes its superfast reactions to a highly evolved sensory system. A film comprised of a series of images flashing by at 20 frames per second can fool the human eye into seeing continuous motion. But flies are capable of perceiving as many as 250 separate images in one second. They can watch the deadly fly swatter as it approaches in what, for them, is literally slow motion – a principle that is equally useful in road traffic. But a lidar sensor puts even a housefly’s awesome high-speed, high-resolution capabilities in the shade. On average, lidar sensors can register several thousand signals every second.