Types of Light That Attract Fall Invaders

Many fall invaders—such as stink bugs, lady beetles (ladybugs), boxelder bugs, cluster flies, and some types of beetles—are attracted to certain kinds of light, especially during their migration into homes and buildings as the weather cools. The specific types of light that attract these pests most strongly are:

• Bright white lights – Lights that emit bright, white, or bluish-white wavelengths (especially those from traditional incandescent bulbs, halogen, and many LED lights) are particularly attractive to most fall invading insects.
• Ultraviolet (UV) light – Many insects are naturally drawn to UV light, which is why you often see them swarming around bug zappers or porch lights that emit bluish-white hues.
• Cool temperature lights – Lights listed as “cool” or “daylight” (with higher color temperatures, usually above 3,500 Kelvin) emit more of the blue and white spectrum, which act like signals to insects searching for warmth or a landmark as it gets dark and cool outside.

On the other hand, lights that are less attractive to fall invaders include:

• Yellow or “warm” lights – Bulbs marketed as “bug lights,” yellow LED bulbs, or any bulbs that produce a warm yellow/orange glow (color temperature below 3,000 Kelvin), are significantly less attractive to most fall pests because these insects cannot see or are less attracted to the yellow part of the spectrum.
• Low-intensity lights – Dimmer exterior lighting or lighting with lower wattage will generally reduce insect attraction, since these creatures navigate by light intensity as well as color.

Why Are Fall Invaders Attracted to Certain Lights?

Fall invaders are cold-blooded insects that start looking for shelter when the temperatures drop. When artificial lights are turned on in the evening, especially around doors, windows, garages, or on siding, these pests are drawn in for two main reasons:

• Navigational confusion – Insects use natural light sources like the moon or stars to navigate. Artificial lights confuse their sense of direction, causing them to circle around lamps, porch lights, or lighted entryways.
• Heat attraction – Some bulbs (especially old-fashioned incandescent or halogen) give off warmth in addition to light, making them even more attractive as nights get colder.

Once insects land near these lights, they often explore cracks, gaps, or screens close to the source, which leads them to enter homes seeking warmth and shelter for the winter.

How to Minimize Light Attraction for Fall Invaders

To reduce the likelihood of attracting fall invading insects with your lighting, you can use the following strategies:

• Replace outdoor bulbs with yellow “bug lights” or warm-toned LED bulbs (labelled as 2700K or below).
• Turn off unnecessary lights in the evening, especially those directly near doors and windows.
• Move outdoor lights farther from entry doors, concentrating them on paths or yard edges instead of right against your house.
• Install motion-sensor lights so that they’re only on when needed.
• Check and maintain window and door screens, weather stripping, and seal entry points to keep insects from getting inside if they are drawn to the vicinity.

By understanding which types of light are most attractive to fall invaders—and choosing lighting that’s less appealing—you can significantly decrease the number of bugs congregating around your home’s exterior and the risk of them entering your living spaces in the fall.