Artificial lighting around homes can influence spider presence. While spiders aren’t directly attracted to light, their presence often correlates with areas where their insect prey congregates. Understanding this indirect relationship is key to managing spider populations around your living spaces.
Understanding How Spiders Perceive Light
Spiders possess diverse visual capabilities, often differing significantly from human sight. Most species have multiple eyes but poor eyesight, primarily detecting changes in light and dark intensity. They largely rely on other senses like touch and vibration to navigate their environment and locate prey.
Some hunting spiders, including jumping spiders and wolf spiders, exhibit more developed vision. Jumping spiders, for instance, can have trichromatic vision, similar to humans, and are capable of seeing ultraviolet (UV) light. Wolf spiders are sensitive to both green and ultraviolet light.
While some spiders can detect colors, their primary attraction to lighted areas is often indirect. Spiders are drawn to places where their food sources, predominantly insects, are abundant. Many insects are strongly attracted to certain light wavelengths, especially UV and shorter wavelengths like blue and green. Insects use these spectrums for navigation and finding food, making illuminated areas prime hunting grounds for spiders.
Strategic LED Lighting for Spider Deterrence
The color of LED light significantly influences insect presence, and consequently, spiders. Cooler, shorter wavelength lights, such as blue and white LEDs, attract more insects. This is particularly true for ultraviolet and blue light spectrums, which are highly appealing to a wide range of insects. LEDs with color temperatures above 3500 Kelvin (neutral white) or higher (cool white/daylight) are more prone to attracting bugs. If a light source draws many insects, spiders will naturally follow to exploit this food source.
To minimize spider presence, choose LED lights that attract fewer insects. Warmer-toned, longer wavelength lights like yellow, amber, and red LEDs are generally less appealing to most insects. Yellow or amber “bug lights” and LEDs with lower color temperatures (2000-3000 Kelvin) produce a warm white to amber glow that significantly reduces insect attraction. Red lights are often the least appealing to bugs.
Practical steps to deter spiders involve strategic lighting choices and placement. Using warm-toned LED bulbs outdoors, such as yellow or amber, can help reduce insect gathering. Limiting outdoor light use to when needed, or installing motion-activated lights, can further reduce insect attraction and spider activity. Minimizing UV-rich light sources indirectly helps by decreasing their prey.