Top: Light from the Sun is polarized when it is scattered by the sky. When the angle of polarization is plotted at different positions on the sky, it forms concentric circles around the Sun (also shown in the background of this figure). Therefore, if an organism can determine the polarization pattern of light from the sky, it can use this information to navigate, even if it cannot see the Sun. Bottom: In Drosophila information about the polarization of light is collected by specialized structures in the dorsal rim area of the eye (not shown) and then transmitted along a dedicated pathway (purple) to the central complex, where it is combined with a representation of the fly’s heading based on the visual panorama. The signals from each eye pass through the dorsal rim region of the medulla, the anterior optic tubercle, and then through the bulbs before reaching the central complex.