Robotic bee for aeronautics research. The apparatus consists of an artificial wing (grey, centre) suspended in a tank of paraffin oil. As the wing flaps in the viscous fluid, it produces turbulence. This is seen by the movement of air bubbles (green) illuminated by a pulsed laser light. Understanding the way in which insect wings work may help in the design of aircraft wings. Photographed at the University of Ulm, Germany.