Insects as Gibsonian animals

Research on the visual behavior of insects has uncovered a number of cues t hat are used for controlling and stabilizing flight and for extracting info rmation about the structure of the environment. Flies monitor their egomoti on and maintain a straight course by sensing the patterns of image motion t hat are induced in the eyes. Bees flying through a tunnel maintain equidist ance to the flanking walls by balancing the speeds of the images of the two walls. This enables them to safely negotiate narrow passages or to fly bet ween obstacles. The speed of flight in the tunnel is controlled by holding constant the average image velocity as seen by the 2 eyes. This ensures tha t the bee slows down to a safer speed when the passage narrows. Bees landin g on a horizontal surface hold constant the image velocity of the surface a s they approach it, thus automatically ensuring that flight speed is close to 0 at touchdown. Flies and bees distinguish objects from backgrounds by s ensing the relative motion between the images of the object and the backgro und. Ranges of objects are gauged in terms of the speeds of motion of the i mages of the objects. Foraging bees estimate the distance that they have tr aveled to reach a food source by integrating the optic flow experienced en route-they possess a visually driven odometer.