Moths aren’t so much attracted to flame as they are disoriented by it. Like many flying insects, moths are able to find their way partly by using light as a compass. When the source of light is the sun or moon, that light source is very distant, and the incoming light rays that strike the insect arrive just about parallel to each other. So moths – and many other flying insects – have evolved to expect to receive light at a fixed part of the eye. As long as the moth flies more or less in a straight line, this visual pattern remains unchanged.
Now consider what happens when the light source is a nearby candle. Then the angle at which the light strikes the moth’s eye quickly changes while the moth holds to a straight-line course. The moth tries to maintain a constant angle to the source – and as it does so, it spirals in toward the light. So the moth seems “attracted” to the light – so much so that it may end up drawn into the flame.
What you saying? Moths are partially blind? What about Daddy Long Legs – they’re the same? It doesn’t really explain why they don’t come out during the day!
Basically the Moths love the moon, and it’s all our fault for making moon like objects which confuse them. I think there is probably more romance in this theory than science. There is no reason to say WHY they like the moon.
But why don’t they appear during the day? The search goes on…
Forget Moths and Light. What I wanna know is why are flies attracted to putrid odours? Why do they lick Sh*t and why do houseflies circle lights in a room? Do flies serve a purpose in this world of ours?
Sorry for going off topic but I’m sitting here in the living room staring at a fly circling the light for 5 minutes. I’m just wondering what the fly gains out of it?
Loving your answer to the Moth question Jon. Now could you shed some light on my fly question?
As for houseflies flying in circles even when the light is off, it’s probably just a coincidence. Flies have excellent vision, when compared with most insects, and their navigation system is actually rather complex. (This is why they are so difficult to catch…..Flies typically fly only during the daytime when they can see the best…)
Their habit of flying around near the center of the room is because it gives them the best view of their surroundings, including potential enemies, mates, or food sources. Coincidentally, this is where the light usually is, whether it on or off…
“To understand this phenomenon, you need to know about phototaxis. Phototaxis is an organism’s automatic movement toward or away from light. Cockroaches are an example of a negatively phototactic organism. You’ve probably noticed how they scurry back into dark corners and crevices when you illuminate their late-night snacking party in your kitchen. Moths are positively phototactic. They seem charmed by your porch light, your headlights or your campfire (even if it leads to their untimely demise). While there is no definitive explanation for this phenomenon, there are some interesting theories.”
As for flies, has anyone noticed an abunandance of brightly coloured ones in the UK this year? Also where do flies sleep then? DO the sleep? This is opening a wormhole of insect debate. Worms too.
Mike there are brightly colored moths nowadays in Sydney Australia but I don’t know why. I’ve never seen them before. They have this very shiny peculiar colors more like pearl green and other pearl colors.
June 30th, 2009 at 11:06 am
And if they like light so much, why don’t they come out in the day?
July 2nd, 2009 at 4:11 am
Moths aren’t so much attracted to flame as they are disoriented by it. Like many flying insects, moths are able to find their way partly by using light as a compass. When the source of light is the sun or moon, that light source is very distant, and the incoming light rays that strike the insect arrive just about parallel to each other. So moths – and many other flying insects – have evolved to expect to receive light at a fixed part of the eye. As long as the moth flies more or less in a straight line, this visual pattern remains unchanged.
Now consider what happens when the light source is a nearby candle. Then the angle at which the light strikes the moth’s eye quickly changes while the moth holds to a straight-line course. The moth tries to maintain a constant angle to the source – and as it does so, it spirals in toward the light. So the moth seems “attracted” to the light – so much so that it may end up drawn into the flame.
July 2nd, 2009 at 5:16 am
its because they’re gloomy doomy…Mothic
July 2nd, 2009 at 8:25 am
What you saying? Moths are partially blind? What about Daddy Long Legs – they’re the same? It doesn’t really explain why they don’t come out during the day!
July 2nd, 2009 at 12:27 pm
i think bright light sources make them go a bit mental
July 2nd, 2009 at 4:03 pm
Here’s another theory on Moth’s and light.
http://everything2.com/node/927362
Basically the Moths love the moon, and it’s all our fault for making moon like objects which confuse them. I think there is probably more romance in this theory than science. There is no reason to say WHY they like the moon.
But why don’t they appear during the day? The search goes on…
July 8th, 2009 at 3:24 pm
Forget Moths and Light. What I wanna know is why are flies attracted to putrid odours? Why do they lick Sh*t and why do houseflies circle lights in a room? Do flies serve a purpose in this world of ours?
Sorry for going off topic but I’m sitting here in the living room staring at a fly circling the light for 5 minutes. I’m just wondering what the fly gains out of it?
Loving your answer to the Moth question Jon. Now could you shed some light on my fly question?
July 9th, 2009 at 3:30 pm
As for houseflies flying in circles even when the light is off, it’s probably just a coincidence. Flies have excellent vision, when compared with most insects, and their navigation system is actually rather complex. (This is why they are so difficult to catch…..Flies typically fly only during the daytime when they can see the best…)
Their habit of flying around near the center of the room is because it gives them the best view of their surroundings, including potential enemies, mates, or food sources. Coincidentally, this is where the light usually is, whether it on or off…
July 9th, 2009 at 4:17 pm
It seems like Dr. Jon is in the house.
But he may have missed out an important factor.
As for flies, has anyone noticed an abunandance of brightly coloured ones in the UK this year? Also where do flies sleep then? DO the sleep? This is opening a wormhole of insect debate. Worms too.
July 13th, 2009 at 2:20 am
Moths come out at night so the birds don’t see them in the daylight….. and they may also be vampires!
January 16th, 2010 at 4:35 am
Good answer Jon, thanks.
Mike there are brightly colored moths nowadays in Sydney Australia but I don’t know why. I’ve never seen them before. They have this very shiny peculiar colors more like pearl green and other pearl colors.