Honeybees can safely land at virtually any angle without problems. How do they do it?
A safe landing requires that the honeybee reduce its approach speed to nearly zero before contact. One logical way to do this would be to measure two factors—flight speed and the distance to the target—and then reduce speed accordingly. However, that method would be difficult for most insects because they have close-set, fixed-focus eyes that cannot directly measure distance.
The vision of honeybees is very different from that of humans who use binocular vision. Honeybees seem to use the simple fact that an object appears to get bigger as they approach it. The closer they get to an object, the faster it seems to increase in size. Experiments conducted at the Australian National University indicate that the honeybee decreases its flight speed so that the rate of apparent enlargement of an object remains constant. By the time the honeybee reaches its target, its speed has decreased to almost zero, allowing it to land safely.
Scientists are amazed by the simplicity and generality of this landing strategy making ideal for implementation in the guidance systems of flying robots.