A number of animals, including honeybees and butterflies, use sunlight’s polarization in their navigations, but the dung beetle is the first animal ever discovered to use moonlight’s polarization to guide its travels. Polarization happens when some of the light from the sun interacts with particles in the atmosphere, causing the light to vibrate along a single plane. Polarized light is invisible to the human eye. It’s been known for some time that the eyes of some insects are sensitive to polarized sunlight, but what is remarkable about the dung beetle is that moonlight is one millionth the strength of sunlight and requires a good deal more of a pair of eyes.