Why are moths and other bugs attracted to lights?

Answer 1

This is an instinctive thing that is believed was needed to get these bugs to get out of caves.
Another theory is that the light helps them migrate.
Another still thinks it is related to being attracted to infra-red. This is to get them to go towards warmth.
No one knows the exact reason. All they know is that it is there.
To see a complete list of theories check out the web site listed below.

Answer 2

Actually the main theory is tha moths are not attrated to lights.

Instead, being nocturnal, they navigate by the moon. They think a lightbulb or flame is the moon, but because it is much closer than moon they end up flying around it in circles.

Ahh, but you say, this makes no sense because moths crash into lightbulbs. The answer is simple, moths, like fighter pilots deliberately don't fly in a straight line. This stops predators eating them, but it means they fly into light bulbs....oops