Some nocturnal insects use the moon to navigate. If they can see the moon the whole time they're flying, they can keep track of the direction they're moving in. Now that electric lights appear brighter than the moon, they sometimes head toward electric lights erroneously.

moths

because they dont have their own bulbs

its cause the bright lights release endorphins for the insects, like chocolate does for us!

+5 Because you are paying the electric bill. They get a free show

Because they left the dark side?

I think it's the heat they're after.

"Moths frequently appear to circle artificial lights, although the reason for this behavior remains unknown. One hypothesis advanced to explain this behavior is that moths use a technique of celestial navigation called transverse orientation. By maintaining a constant angular relationship to a bright celestial light, such as the Moon, they can fly in a straight line. Celestial objects are so far away, that even after travelling great distances, the change in angle between the moth and the light source is negligible; further, the moon will always be in the upper part of the visual field or on the horizon. When a moth encounters a much closer artificial light and uses it for navigation, the angle changes noticeably after only a short distance, in addition to being often below the horizon. The moth instinctively attempts to correct by turning toward the light, causing airborne moths to come plummeting downwards, and - at close range - which results in a spiral flight path that gets closer and closer to the light source. In 1972, Henry Hsiao, now a professor of biomedical engineering, suggested that the reason for moths circling lights may have to do with a visual distortion called a Mach band. He says that they fly towards the darkest part of the sky in pursuit of safety and are thus inclined to circle ambient objects in the Mach band region. Hsaio says that the celestial navigation theory should cause moths to circle lights, not to head directly toward them, as many are seen to do. He conjectures that moths, which are nocturnal creatures, must find a place to hide from predators when daylight comes, but cannot do so in darkness. Their instinct when morning comes is to fly toward the light (presumably up) and then down again, with some probability landing on a surface which matches their camouflage. A theory which has been advanced in an attempt to explain the attraction male moths have for candles specifically is based on olfaction. There is evidence that olfaction might be, in some cases, mediated by detection of the infra-red spectra of substances. The spiky infrared spectra of a candle flame happens to contain a number of emission lines which coincide with the vibrational frequencies of the female moth's pheromone. The male moth is thereby powerfully attracted to the flame. Other sources with different spike patterns, eg. hurricane lamps, are less powerful attractants. Night-blooming flowers usually depend on moths (or bats) for pollination, and artificial lighting can draw moths away from the flowers, affecting the plant's ability to reproduce. A way to prevent this is to put a cloth or netting around the lamp. Another way is using a colored light bulb (preferably red). This will take the moth's attention away from the light while still providing light to see by." Source and further information: http://en.wikipedia.org/wiki/Moth#Attraction_to_light "The species is attracted to light, like many other insects." Source and further information: http://en.wikipedia.org/wiki/Labidura_riparia "Lepidopterists and entomologists have documented that night-time light may interfere with the ability of moths and other nocturnal insects to navigate." Source and further information: http://en.wikipedia.org/wiki/Light_pollution Further information: http://en.wikipedia.org/wiki/Bug_zapper - "Why are insects attracted to light?": http://www.wisegeek.com/why-are-insects-attracted-to-light.htm - "Why are insects attracted to light?": http://blogs.nlb.gov.sg/ask/children/119 - "Why are moths and other insects attracted to lights?": http://ask.yahoo.com/20030708.html

Some insects like moths that are nocturnal and are attracted by moonlight or a lamp have a waking system similar to people. We go to bed at night and become active and wake up to the sun and daylight. Nocturnal moths navigate by moonlight but daytime moths rest at night and wake to the sun and daylight.