light

Well, the sort of standard line of explanation is that it's something of an evolutionary short circuit that moths and other nocturnal insects use celestial navigation for orienting about in the dark, the same way that explorers could find their way by charting a course relative to the North Star or some celestial far-distant point source of light. And what has happened since that time is that humans have come along and developed terrestrial point sources of light. So very intense light that is not millions of miles away. So in a behavior called transverse orientation, many animals, including insects, can move or fly to maintain a constant angle relative to a distant point source of light.