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Are Bugs Attracted to Light?

bugs attracted to light

Whether it’s a bulb on your front porch or a lamp out in the backyard, it seems that there are always bugs flying or crawling around that space. At any given time, it’s easy to see a variety of insects flocking towards the light. Why are bugs attracted to light around the exterior of your home when the sun goes down?

Are Bugs Attracted to Light?

The short answer to the question is what you are probably suspecting: yes, bugs are attracted to light. You probably have more questions about insects and light, however. Are there certain types of bugs that seem more drawn to outdoor lighting? What is it about light that seems to attract insects? Most importantly, what should we know about this phenomenon which can help us keep pesky insects away from our entryways, so they don’t make it inside? How can we keep insects from bugging us when we are in our yards at dusk and at night?

Which Bugs Like Light?

Before we understand why insects flock towards light, it’s important to know which bugs are most attracted to it. The most common bug we see around our light sources is the moth. Other flying insects also drawn to the lights on our porches, in our yards and on our streets are:

  • mosquito hawks
  • fireflies
  • beetles
  • bees
  • wasps

Bugs that crawl, like ants and non-flying beetles, can also be found near your home’s lights.

Theories About Insects and Light

There are a few theories as to why light attracts a number of flying bugs, like moths, fireflies and beetles. One of those theories is called phototaxis, or the way an organism moves towards or away from a light source. If a bug flies towards the light, it’s referred to as positive phototaxis; bugs that scurry away, like cockroaches, are an example of negative phototaxis.

At night, flying bugs use natural light sources, such as the moon and stars, to navigate their path. So when you turn on your porch light, many nocturnal bugs mistake the artificial light source as their guide.

A similar theory relates to an insect’s internal navigation system, or the way an insect flies in relation to the moon. Flying bugs travel at a constant angle relative to a distant light source. Artificial light can interfere with an insect’s navigation system and change the angle of flight. As a result, a bug might change its trajectory to fly closer to artificial lights.  

Yet another theory involves a moth’s mating process. According to an entomologist in the 1970s, the infrared light spectrum emitted by a candle flame gives off similar frequencies as a female moth’s pheromones or sex hormones. As a result, the theory suggests that male moths might be attracted to flames or similar light spectrums because they think the flames are females sending out sex signals attempting to mate.

Lack of Consensus About Bugs And Light

There are a few problems with these theories, however. One of the reasons many scientists challenge the theory of phototaxis is the fact that humans have been creating unnatural light sources, like man-made fires, for example, for thousands of years, and insects haven’t been flying into those light sources. Researchers also point out that many moth species aren’t migratory, so they wouldn’t use the moon to help guide them on their journey.

The hypothesis about insects and mating signals also has a few potential problems. For one, entomologists believe that ultraviolet light is far more attractive to insects than infrared light. Since UV lights don’t emit the same wavelength as a female’s pheromones, insects like moths shouldn’t be attracted to this type of light.

How to Keep Bugs Away From Outdoor Lights

While there is no scientific consensus about why bugs are attracted to light, there are a few things you can do to minimize the number of bugs flying around your home’s light sources. One of the first things you’ll want to do is check what kind of light bulbs you’re using. Mercury vapor lights, for example, attract the highest number of insects, so much so that entomologists use them to capture certain species. If possible, avoid incandescent and fluorescent bulbs as well, as they can also attract bugs.

Once you’ve removed those bulbs, consider installing warm-colored LED bulbs. Doing so can help reduce the insect activity around your outdoor lights at night.

ABC Knows Pests

If you find yourself with a bug infestation, indoors or outside, give ABC Home & Commercial Services a call. Our experts will effectively assess the situation and provide a solution that’s right for you and your family. We’ll do the work so you can get back to enjoying your evenings outdoors.

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