Three Reasons Why Spiders Can’t Burrow Through Human Skin

Australia's redback spider (Latrodectus)


Yesterday, you may have seen this amusing-yet-dismal failure of the news media. Hundreds of outlets breathlessly reported a tourist’s tale of a skin spider plowing a pustulated trail through his belly. Snopes dissects why the story is bogus; essentially, the sole source is the tourist himself. The poor kid was likely told he had scabies mites, or similar common affliction, and not knowing what a mite was he settled on the nearest arachnid he recognized. That, plus ingrained cultural arachnophobia and a media disinclined to turn down click revenue over such a silly matter as ethics, and the story goes viral.

Shoddy journalism aside, there is no plausible reason for any spider to burrow into skin, and no physical attributes that would allow them success at it, either. Spiders can’t do it for the same reasons giraffes can’t hover: the laws of physics just don’t work that way, not for the way spiders are built. Here are a few reasons why the story simply could not have happened as reported.

1. Spiders are active animals that need to breathe. That’s hard to do when trapped under skin, and spiders lack the breathing tubes of real skin-burrowers like botfly.

2. Spiders are too delicate. Animals that burrow are strong, compact, and stubby. Think of the bullet-like build and short, powerful legs of a mole or a wombat. Serious burrowers like earthworms lack legs altogether. What’s a spider? Pretty much the opposite. Inconvenient legs everywhere, and far too spindly and weak to burrow. (A few spiders do make soil burrows, but soil is a rather different and more forgiving medium).

3. Spiders lack an implement for opening a suitable entry hole. Spiders have fangs, which are thin and sharp and can appear scary, but if you’ve ever tried to dig a hole using only hypodermic needles you’ll appreciate the uphill battle a spider faces.

Also, there has never been a single confirmed observation of a skin-burrowing spider.

So, no. You don’t have to worry about skin spiders.

10 thoughts on “Three Reasons Why Spiders Can’t Burrow Through Human Skin”

  1. I’d like to see a journalist take the time to do a scientific analysis of spiders with regard to this “story” and not just jump on the yellow journalistic bandwagon of “spider fear”. Ethical journalism would dispel falsehoods and myths and educate readers.

  2. It happened to me as a child. I had these little red bubbles coming out in a straight line down my right arm. Doctors at Mayo Clinic in Rochester (where I lived) asked me if they could take away one of the red bubbles. I agreed but knew nothing about it afterwards. The “thing” went away with a simple ointment.

    1. Sorry, MrILoveTheAnts, I was so preoccupied still thinking about cell phone signals causing colony collapse in Honeybees, that I never considered that possibility !

    1. I see what you did there, trying to blame NIH for diverting research money away from The Ebola Cure by working on hairy nasty spiders that could possibly burrow under your skin. But it says ‘boluses’ even in the abstract, so you can kiss that effort goodbye straightaway.

  3. Reminds me of a co-student working on ants in Columbia who had a bot fly embedded in his shoulder. Let it grow to maturity there so he could collect the adult.

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