[Zachthemac]

I know this is a pretty basic question, but why are many insects attracted to lights? Also why do cochroaches scatter when a light is turned on when other insects would go towards it?

[Chris4]

They use the moon to migrate. thats the basics of it. isn’t it?

[opuntia]

quote Zachthemac:

Also why do cochroaches scatter when a light is turned on when other insects would go towards it?

It’s cockroaches move away from light because they have negative phototaxis and some insects are attracted to light because they have positive phototaxis 🙂

[James]

Insects such as moths are positively phototactic, they move towards light, perhaps for navigation, or a natural reaction to move away from the ground if disturbed, away from ground predation. Also, different organisms are attracted to different light intensities, eg moths are attracted to moonlight, but not sunlight, and opposite for butterflies.

[Chris4]

There are some moths which fly in the daytime. Just to confuse things 😆

[Lalalathemonkey]

Do centipedes have a negative phototaxis or a positive phototaxis?[/quote]

[kiekyon]

not all insects are attracted to light for the simple reason that not all insect have the same vision. the same thing goes for human. basically, our vision allows us to see only a small part of the electromagnetic spectrum.

for further reading see http://www.madsci.org/posts/archives/jan2000/948507632.Zo.r.html

[flint]

a lot of insects use the angle of the suns rays for navigation

because the suns rays are coming from so far away the angle will always remain essentially the same

however, when a source such as a light bulb is emitting light (especially at night) the insects now orient to the angle of the rays from that light bulb

because the light build is so small the angle of the rays from the bulb changes as the insect flies around it, thus causing the homing behavior that many insects exhibit towards lightbulbs

[February Beetle]

quote kiekyon:

not all insects are attracted to light for the simple reason that not all insect have the same vision. the same thing goes for human. basically, our vision allows us to see only a small part of the electromagnetic spectrum.

for further reading see http://www.madsci.org/posts/archives/jan2000/948507632.Zo.r.html

Wouldn’t cockroaches still go away from the light because they don’t like the light, not that they have different vision? Or, is all this behavoir based on the insects vision? I just assumed cockroaches didn’t like being in the light but maybe it is because of their vision, hmmm…

[flint]

some insects have a positive phototactic response (towards light) and others have a negative phototactic response (away from light)

so basically, yes, cockroaches go away from light because they dont like it

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