ABSTRACT
One of the most staggering behavioural abilities of some insect species is to use the pattern of polarized light in the daytime sky as a compass. F. Santschi had already noticed that ants were able to navigate correctly even if they could not see more than a small patch of the blue sky, and von Frisch later demonstrated in bees that it was the polarized light in the sky of which the insect made use under such conditions. The bee's internal representation of the celestial canopy, its celestial map, comprises only those e-vectors which lie in the highly polarized part of the sky. It is even in the highly polarized part of the sky that the bee's celestial map does not coincide exactly with any one pattern of polarization present at any time of the day. Instead, the bee's celestial map reflects the mean distribution of e-vectors that lie along the line of maximum polarization.
