Yellow lights are sometimes sold as “bug lights” and promise not to attract insects. And it makes sense — sort of. It’s true that many insects are least attracted to yellow light and more attracted to ultraviolet light, like those used in bug zappers. But depending on which insects you’re trying to avoid, it may not make a difference.

Different colors of light have different effects on insects. Let’s take a look.

What are Bug Lights?

Bug lights are yellow lights that are supposed to attract fewer insects than brighter lights. They’re often marketed for use on your porch or deck to help you avoid attracting insects like mosquitoes. Traditionally, they come as incandescent or CFL light bulbs, but recently, more LED variants are doing well in the market.

How do Bug Lights Work?

Phototaxis

Phototaxis is when an organism, like an insect, responds to light stimulus by either moving toward or away from it. There are many theories concerning why insects are phototactic. Here are a few:

They use light as a navigational tool. Nocturnal insects may navigate using the consistent and predictable light provided by the moon and stars.

They use light as an indicator of a safe place to flee. Light might indicate an opening through vegetation, which an insect can use to escape a predator

They are looking for food. Flowers and other food sources reflect light that insects use to identify them. Certain wavelengths might be mistaken for the colors insects associate with flowers.

Ultraviolet Light versus Yellow and Red Light

Because of the way their eyes are built, many nocturnal insects can see ultraviolet light but have trouble seeing warm-toned lights, like yellow lights. And red lights are completely invisible to them. In fact, researchers use red lights to observe nocturnal insects without disrupting their behavior. This is why yellow bug lights won’t attract certain insects.

But while many bugs won’t see yellow and red lights, there are still those that can. Including:

Flying insects, such as moths and beetles. These insects use light to navigate and are sensitive to light pollution, including that from yellow light.

Biting insects, such as mosquitoes. Yellow light might not save you from insects like mosquitoes, who are not only sensitive to yellow light, but also are attracted to exhaled carbon dioxide. The color of light is irrelevant if they can sense your presence anyways.

Stinging bugs, such as bees. Luckily, most of these insects are active during the day.

Crawling bugs: Many crawling insects are attracted to yellow light. However, they move slowly and aren’t as likely to get close to the bulb in the same way as flying insects.

There are also many insects that are not attracted to either of the two and that swarm for different reasons entirely, such as the presence of a food source or a smell they’re attracted to.

Which Bug Light Should I Use?

Traditionally, bug lights come as incandescent bulbs or CFL bulbs. The best bug light you can use right now are warm-toned LED lights. In addition to being inexpensive, they’re also energy efficient and will last a long time.

Bug Light Alternatives

Bug Zappers

If you want something that will instantly kill unwanted, light-attracted insects, installing a bug zapper outdoors or inside a room may help. Instead of repelling insects by using light that they cannot see, bug zappers use cool-toned light to attract them. These items entice insects to move closer until they reach an area where they’re zapped and killed by electricity.

The downside is that bug zappers kill indiscriminately, and beneficial insects will also be killed. You also might not eliminate as many mosquitoes as you’re hoping to, since they’re more attracted to exhaled carbon dioxide than they are to light.

Aromatics

There are many scents that help greatly with repelling insects. You can use essential oils and aroma diffusers to disperse the scent throughout your house. Common insect repelling scents include citronella, peppermint, and lavender. Alternatively, if you have the ingredients, you can make spice bags and leave them in areas around your house that bugs frequent.

Smoke 

Citronella candles and wood smoke from a fire might also help keep bugs at bay. It’s no guarantee, but if you’re camping and forgot the bug spray, sticking close to the fire might help.

Screens

Keeping bugs out of your house is a great place to start. Screened doors and windows with fine mesh can keep insects from becoming a bother indoors.

Bug Spray 

This method is the go-to for many people. Commercial bug sprays not only poisons the insects that are near you, but it also deters other bugs from coming to your area because of its lingering smell. If you’re uncomfortable with using chemicals, you can make your own DIY bug spray using heavily diluted essential oils in a spray bottle.

Tidying Up 

One of the best ways to prevent any type of insects away is to keep things tidy. Remove clutter, both inside and out and make sure to keep food picked up and put away.

Don’t leave standing water outside — it makes a wonderful haven for mosquito eggs and larvae. Other insects will also be attracted to water. Also, make sure to keep lids on trash cans and have them cleaned periodically — you’ll prevent odors and keep insects from using your trash to hatch eggs.

Call the Exterminator

If you have more insects than you can handle with just a change in lighting, give an exterminator a call. In addition to helping eliminate your problem, they can also offer tips to keep insects away and might have some product recommendations too.

A Word of Caution

Insects are a very important part of nature and our ecosystem because they serve as prey to many other animals and help with pollination. But because they’re seen as pests, they’re prone to over killing.

If you have insects around your house, consider whether it’s possible to leave them alone. Insects also face threats from light pollution, which interferes with their activity, among other things. Yellow lights might be part of the solution, but also consider installing motion-sensor lights that turn on only as needed.

While bug lights are tools that provide an easy and harmless method of avoiding some insects at night, they do come with limitations. Some nocturnal insects are attracted to yellow light, and others, like mosquitoes are attracted to people, regardless of the color light bulb used.