If moths are nocturnal, why are they attracted to light???

Question

If moths are nocturnal, why are they attracted to light???

Answer 1

Moths actually use the moon to orient themselves during nocturnal flights. Since the moon is far enough away that the direction from which its light hits the insect is fairly consistent, it works like a visual compass for the moth. So long as the moth travels perpendicular to the direction of the beams of moonlight, it will fly more or less straight. Unfortunately, moths have trouble distinguishing between the moon and other sources of light, such as open flames or artificial lights. It's not so much that they are attracted to the light, but rather that such a close light source makes their internal navigation system go haywire. They're trying to travel perpendicular to the artificial light source, but they end up "orbiting" the source in ever shrinking circles until they hit it. A better illustration of this can be found in Richard Dawkins' The God Delusion, although some people don't quite buy reorientation reason. One thing most theories have in common is the idea that the moths are not attracted to, but rather confused by the bright lights.

Answer 2

Lots of people quote the "navigating by the moon" theory, but it doesn't stand up to a thorough examination, even though David Attenborough himself gave it as the explanation.

Moths don't circle around the light, they fly straight into it. They seem to be actually attracted to it. It can't be the case that all moths happen to be heading in the same direction, towards the moon.