Why Do Moths Fly to Light?

[lday at iquest.net]

I have to say I find the "navigation by the moon/stars" theory very
implausible.  

First of all, why would moths need to navigate?  They don't need to
go anywhere in a straight line.  They search for food, or mates, or
leaves to lay eggs, which could all be done much better by smell.
I don't THINK they travel or migrate, do they?  Animals that
have these specialized senses for navigation are usually ones that
travel for some distance for some reason.  e.g. bears travel many miles
to seasonal feeding areas, or to new territories.  I thought moths either
moved randomly, stayed near their food/habitat, or followed chemical
cues.

Second, if the moon is so important, why are moths most active on
humid, cloudy conditions when the moon and stars are covered over?

Third, I am more convinced by the suggestion of a (much more knowledgeable
than I) friend who thinks moths hear the light rather than see it, or are
following certain wavelengths.  He says that moths are attracted also to
(I think I have this right) microwave-emitting towers.  (This should be
easy to test, anyone have a microwave oven?)  

I dont' fully understand his explanation, but the moon/star one just
doesn't make any sense either.  Is there ANY research on this topic?


Liz Day
LDAY at iquest.net 
Indianapolis, Indiana, central USA, 40 N latitude, zone 5.
http://www.iquest.net/~lday