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The Debunker: Are You Within Three Feet of a Spider Right Now?

by Ken Jennings

Mathletes probably know that March 14 is celebrated as "Pi Day," because 3/14 is a natural time to salute the decimal approximation of pi, 3.14. But if you're a science nerd who's more into biology than physics, you'll be happy to know that March 14 is also National Save a Spider Day in the United States. March is the perfect month to thank our arachnid friends for all they do for us—especially because they're so often misunderstood. Here, let's allow Jeopardy!'s Ken Jennings to smooth out the tangled web of spider myths that might have you deceived.

The Debunker: Are You Within Three Feet of a Spider Right Now?

I debunk a lot of weird stuff on this website, but this oft-repeated factoid is a unique kind of a thing even for me: a trivia fact that presumes to know an awful lot about my current situation. Really? I'm three feet from a spider at all times? Even if I'm swimming in a hotel pool? Skydiving from a plane? Trudging across the Antarctica tundra? How does nature guarantee my spider proximity in situations like those?

The Debunker

The originator of this slightly presumptuous misconception appears to be Norman Platnick, a curator and spider expert at the American Museum of Natural History. He began a 1995 article by claiming, "Wherever you sit as you read these lines, a spider is probably no more than a few yards away." Platnick was making the point that spiders are near-ubiquitous in most ecosystems, and rarely noticed. But he hadn't done any involved math on the subject. He was just trying to grab lay readers with a fun intro.

Spider expert Rod Crawford agrees that a few feet or yards is a safe bet for most people in the great outdoors. In fact, on a grassy lawn, you could probably amend Platnick's guess to "a few inches," because ecosystems like that average at least fifty spiders per square meter. In forests, it might be a tenth that; in particularly spider-dense pastures, the count might be ten times as high. But in non-natural settings, Crawford says (imagine a paved parking lot or a well-fumigated building) you shouldn't be surprised if your nearest spider is hundreds of feet away. I hope that's a weight off your mind. If you want absolute spider-free certainty, though, stick to swimming or skydiving.

Quick Quiz: : In 2017, a tech company called Energous received a patent for its "WattUp" technology, which enables you to do what from three feet away?

Ken Jennings is the author of twelve books, most recently Planet Funny and co-hosts the most important podcast in human history, Omnibus. He's also the proud owner of an underwhelming Bag o' Crap. Follow him at or on Twitter as @KenJennings.