Last night I discovered thousands of wolf spiders staring at me in my backyard

by | Sep 20, 2010 09:59 AM ET

This weekend I was cleaning my desk and I found my headlight lamp. This is a little LED flashlight with a strap that you wear on your forehead, like this one (mine isn't quite this fancy).

So you know how, once you find or buy something like that, you want to try it out? Me too. So I strapped mine on, called the dog and went out into the backyard. I have been doing a big yard project, so there are some piles of dirt in the back yard.

I turned my head and shined the headlight on one of the piles, and the strangest thing happened. It sparkled. The pile of dirt had all these reflections coming off of it. I stood facing the pile and looked at it. Still sparkling. This is a very poor photograph of what I saw:

The upper reddish part is dirt. The lower part is grass. You can see 9 or 10 bright spots, which are the reflections. In reality there are more than that, I guess because you can shift your head slightly and new ones appear. The flash captures a single angle for an instant.

What could that be? I assumed it was mica or quartz crystals or something in the clay. So I walked up closer to investigate. And every one I investigated revealed... a wolf spider:

Yes. Wolf spiders. Apparently the reflection is coming off of their eyes, sort of like red eye in humans and animals.

The amazing thing is the number of spiders. There are literally thousands of reflections in the yard. And I imagine half the spiders are facing the other way. That's a lot of spiders.

So I want to make sure I am not hallucinating about the effect or the number of spiders. I grab Leigh, take her outside and put the headlight on her head. "What do you see?" I ask her. I have not told her a thing. "You've discovered diamonds?" she says. She is seeing the same reflections. You don't see it with a normal flashlight. I guess the light has to be close to your eyes to get the angle of reflection right. I tell her to go investigate one of the reflections. She is not particularly happy. Then I show the kids one by one. They all see it too. We went on a spider hunt. They are far more excited than Leigh.

Of course this is not a new discovery. When you plug the idea into Google you can find pages like this:

Headlighting for Spiders

Wandering spiders like the wolf spiders (Lycosidae) (Fig. 2) and fisher spiders (Pisauridae) may be spotted with the head lights. The beam should be aimed at the ground or toward low vegetation about fifteen feet ahead of you. Move the beam very slowly until you see a small shining spot resembling a tiny star--the spider's eyes. Move toward the spot carefully, making sure not to lose it. The spider seems to be blinded and will not move as actively as when you approach one during the day. When close enough, capture the spider in a bottle. The easiest way is to invert the bottle and quickly place it over the creature.

You might want to try it one night. I live in North Carolina - if your location is anything like NC, there are thousands of spiders out right now.

More info:

- How Light Emitting Diodes Work

- How Spiders Work

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