Does Green Light Really Attract Wolf Spiders?

Finding a wolf spider in your home can be frightening, and though these arachnids will sometimes bite when threatened, they aren't dangerous. If you're wondering why these spiders keep popping up near your home, you might want to consider the colors of your home's exterior and interior, as well as the lighting you're using. A professor of biology at the University of Cincinnati, George Uetz, found that wolf spiders seem to enjoy green light. Because spiders have dichromatic vision, they are only able to detect ultraviolet and green colors. "That means they're basically colorblind. But they're sensitive to light in the green wavelength," Uetz said in a presentation at the American Arachnological Society in 2018. 

Because of this, wolf spiders are likely attracted to green lights since they can really see the color. Though wolf spiders like to live in dark areas, they may be attracted to the bugs swarming around your exterior lights, whether they're green or not. To keep wolf spiders away from your home, try avoiding the color green and turn off lights to keep bugs away and cut out the arachnids' food source.

Why wolf spiders are attracted to green light

When George Uetz and his team studied wolf spiders, they discovered that the female spiders were more interested in videos of male wolf spiders that had contrasting background colors — while males were drawn to the colors they could see, including green: "What we found is that for female spiders, intensity matters more than color. But for male eavesdroppers, color matters, too. That is the odd finding. We didn't expect that at all," Uetz said at the 2018 conference.

Though spiders may be attracted to green light and the color green in general, this doesn't mean you won't find them around exterior lights of other colors. Since flying insects often hover around light sources, wolf spiders will stay nearby to hunt their prey. If you aren't scared of spiders, leaving up green lights could allow these helpful arachnids to stick around and kill other insects near your home.

How to deter wolf spiders

For those with arachnophobia, having wolf spiders in your house or your yard can be a nightmare. If you're noticing an abundance of these spiders outside your home, they could be hunting insects on your property. To eliminate or lessen the arachnid's food supply, try leaving outside lights off at night when they hunt. Alternatively, you could try using motion sensor lights, which would only turn on for short periods when someone walks by and attract fewer insects. While green lights are less likely to attract other insects, they could bring more wolf spiders to your home, so you may want to avoid this color to keep these arachnids away.

Wolf spiders are also known to hide in piles of leaves, cardboard boxes, and other dark areas in yards. Getting rid of any outdoor clutter and keeping up with lawn maintenance can help make the environment less inviting for wolf spiders. Though wolf spiders do respond to green light, you're likely to find them wherever there are insects to munch on.