We’ve all heard this scary and unsettling factoid; It says that as we enjoy our beauty sleep, we inadvertently consume up to 4 creepy crawlers per year. Thinking of eating spiders while we sleep is certainly a thing of nightmares, but is there any truth to this fact? Do you really eat 4 spiders a year in your sleep?
You Can Rest Easy
Thankfully you can rest easy tonight, it’s just an urban legend. Realistically, the average number of spiders swallowed at night per person per lifetime is probably less than one.
It’s actually quite hard for a spider to get near your mouth while you’re sleeping. First, you must have your mouth open, which is not universal since many people sleep with their mouth shut. Someone sleeping with their mouth open would also most likely be snoring which ties into the second reason.
Secondly, there has to be a wandering spider in your immediate vicinity — something, which for most people in the civilized world, is a fairly rare occurrence. As you sleep, your breathing, movements, even your heartbeat creates vibrations which spiders perceive as a threat. A spider’s entire world revolves around detecting vibrations and acting on them, whether its feeling prey struggling in its web, or detecting the vibrations of a predator approaching. A sleeping human would be a giant, ringing gong of danger to most spiders.
And thirdly, the unlucky spider has to either jump or fall into your mouth from a distance. Why a distance? Because spiders usually will not go near your mouth otherwise. They will flee from your breath (it’s not evolutionary beneficial to stand around while something is breathing on you). The odds of a spider randomly or accidentally falling into your open mouth from the ceiling are pretty astronomical, higher than getting struck by lightning.
How did the myth begin?
This rumor was started in 1993 by Lisa Holst, a columnist for a computing magazine. She wrote an article which focused on the increasingly common lists of supposed “facts” that had begin to circulate on the internet in the 1990s.
To make her point, Holst made up her own list of supposed ‘facts’. One claimed that the average person swallows up to four spiders per year. She took her inspiration from collection of common misbeliefs printed in a 1954 book on insect folklore. It is, of course, wonderfully ironic that Holst’s “false fact” has since become one of the most widely spread myths on the internet.
Bonus Spider Fact: Only the female black widow spider has a poisonous bite. The male spider’s venom is not poisonous and it does not attack its prey. Also, the bite from a black widow spider is not automatically fatal. In fact, less than 1% of all people bitten by this spider run the risk of dying, as most of them are saved with the use of antivenin.
Holst, Lisa Birgit. “Reading Is Believing.” PC Professional. 7 January 1993 (p. 71)
Domke, Ellen. “Average Folks Need to Keep Mouths Shut.” Chicago Sun-Times August 1997 (p. 20)
The Pedant’s Revolt. Delacorte Press, October 2005 (pp. 21-22)