perceiving the sky as blue

“Wehner demonstrated that the ants use skylight as a compass cue and that their visual systems are especially sensitive to the patterns of polarized light in the sky.

These patterns are created when rays of sunlight entering earth’s atmosphere collide with air molecules and other particles and scatter in all directions. Because most scattering takes place in the blue and ultraviolet wavelengths, we perceive the sky as blue.” source :national geographic