The idea that spiders “hate” a specific color of light is less about a true phobia and more about a biological incompatibility with certain wavelengths. Spiders navigate and hunt using environmental cues that bright, artificial lights can disrupt. The colors that effectively deter them do so primarily by interfering with their ability to find food. Understanding how spiders perceive light is the first step toward using lighting strategically for pest management.
How Spiders Perceive Light
Most spiders possess up to eight simple eyes, or ocelli, which generally do not form sharp, high-resolution images. Instead of relying on detailed sight, the majority of spiders use their eyes to detect changes in light intensity and motion. This limited visual capacity means that most spiders are dichromatic, perceiving a restricted range of color.
Their photoreceptors are primarily sensitive to light in the green and ultraviolet (UV) parts of the spectrum. The ability to see UV light is particularly significant because it plays a role in how many insects, which are their prey, navigate. Certain active hunters, such as jumping spiders and wolf spiders, possess more advanced vision, allowing them to see a broader spectrum, including red, orange, and yellow hues. Even with this expanded vision, their world is still fundamentally different from ours, with colors often serving as signals for courtship or warning rather than as detailed environmental features.
The Specific Light Colors That Deter Spiders
The colors of light that spiders tend to avoid are those in the longer wavelength range: yellow, amber, and red. This aversion is largely an indirect consequence of their diet and vision. Spiders are not strongly attracted to light itself; rather, they are drawn to the congregations of insects that gather around bright light sources, serving as an easy food supply.
Shorter wavelength light, such as blue and ultraviolet, is highly attractive to flying insects, including moths, mosquitoes, and gnats. This is because it mimics the natural light cues these insects use for navigation. Lamps that emit high amounts of UV and blue light, such as traditional white LEDs and mercury vapor lights, create a concentrated feeding ground that spiders will readily exploit.
Conversely, light with longer wavelengths—yellow, orange, and red—is less visible to many nocturnal insects. Sodium vapor lamps and specific yellow- or amber-tinted LEDs filter out most attractive blue and UV light, reducing the insect population around the fixture. By eliminating the spider’s food source, these warmer-colored lights indirectly but effectively deter spiders from inhabiting the area. Therefore, the “color spiders hate” is a light spectrum that denies them a reliable hunting opportunity, rather than a color they actively flee from.
Using Light for Spider Management
Applying the science of spider vision and insect attraction provides practical ways to manage spider populations around a home. The most straightforward approach is to replace exterior lights with fixtures that emit light in the warmer end of the spectrum. Look for “bug lights,” which are typically yellow or amber-tinted incandescent or LED bulbs, or LEDs with a color temperature of 2000K or lower. This low color temperature signifies a warmer, orange-yellow light that lacks the blue light that attracts insects.
Strategic placement of lighting is also important, as light deterrence only works when the light is present. If a porch or doorway frequently hosts spiders, consider using motion-sensor lights or timers to minimize the amount of time the light is on. Positioning lights away from the house, or directing the beam away from windows and doors, can draw insects and, subsequently, spiders away from potential entry points. While changing the light color will not eliminate spiders already present, it is a simple, non-toxic method that can significantly reduce the number of spiders that build webs near living spaces over time.