Summer is here, followed by monsoon and with it the main season of flies, mosquitoes, moths etc. It is the time when the insects get lost in our homes. Insects seem to be magically attracted to ceiling lights as much as to car headlights and street lights. But why are insects attracted to light?

Why Insects are attracted to light
©Ashley Cooper/ Corbis

This has not been clarified yet, however, there are many theories to why are insects attracted to light. Research currently assumes that nocturnal insects are based on the celestial bodies, i.e. the moon and the stars. If we follow the so-called navigation theory, the animals use street lamps as soon as they shine brighter than the moon, which is usually the case.

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But, from an insect’s perspective, while the moon is almost still in the sky and the animals only have to keep a certain angle to the moon in order to fly straight ahead, the position of a lantern changes very quickly as it flies by. The moth is now trying to keep the same angle to the lantern as to the moon and that’s where the difficulty begins.

Because the insect is forced to constantly correct its course, as a result, it inevitably flutters towards the lamp in spiral paths.

Another theory says that insects generally fly on light, but avoid high light intensity and therefore direct their flight towards the boundary between light and shadow. This could also explain why the insects swarm in spiral paths around the light source.

Moths Don’t Find Light Attractive – Why Are Insects Attracted To Light?

According to this theory, Butterflies or moths cannot help but fly to the light even though they don’t find light attractive at all then why are insects attracted to light?. It’s the UV component of the light that attracts them. The light source is the only thing the animals see like in the tunnel effect.

All around that is absolute darkness for the insects. The stronger the contrast between the light source and the surrounding lighting, the more insects a light source usually attracts. The moths are blinded and their ability to orientate fails.

Insects and Lights Relation

Insect traps also take advantage of the fact that insect eyes react sensitively to ultraviolet radiation which is much more sensitive than humans. In these devices, the blue light is often combined with a heating tube. The insects fly up and sizzle due to the electric shock. In contrast, the animals are far less susceptible to wavelengths in the yellow, orange or red range.

Once the moths have reached the light source, this usually means death. For example, they die on impact with the lamp, burn their wings, remain trapped in the lamp housing and starve, or become easy prey for spiders and bats. Around 150 insects are killed per street lamp and night in the summer and monsoon months.

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The specific reason for Why are insects attracted to light might not be verified but these theories might be specific and true to certain insects and other theories for other insects That is why yellow lights or no lights are so important for insects.

Yellow light is favourable for extending the life of insects because they are not only at the bottom of the food chain but also because they are responsible for existence and survival of all other living beings and species.

Hope this solves your query as to why are insects attracted to light?

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