Lights off, head on the pillow, and then it pops into mind: the old claim that people swallow eight spiders a year in their sleep. It’s a classic bit of pub-quiz trivia, and spider experts aren’t convinced. Spiders are very unlikely to end up anywhere near a sleeper’s mouth, and the reasons are surprisingly reassuring.
The lowdown: People don’t swallow eight spiders a year in their sleep, and there’s no recorded case of anyone swallowing even one. The vibrations from breathing, heartbeats and snoring are likely to put spiders off, and a spider crawling across a face would probably wake its owner first. Even the popular story about where the myth started has turned out to be a hoax.
Swallowing spiders in your sleep is a myth. Spider experts point to five reasons a sleeping person is about the last place a spider would want to be.
Experts at Seattle’s Burke Museum describe the swallowing claim as an urban legend with no basis in fact. No case of a sleeper swallowing a spider appears in the scientific or medical literature, and no one watching a sleeper has ever reported seeing it happen.
Breathing, a beating heart and snoring all create vibrations, and spiders rely heavily on vibrations to sense the world, arachnologist Rod Crawford told Scientific American. A sleeping human may be something a spider would much rather avoid than explore.
To a spider, a person is about as interesting as a big rock, according to biologist Bill Shear. Beds hold little appeal for spiders, since there’s usually no prey to catch there. A spider has no reason to head into a sleeper’s mouth, according to Dr Geoff Oxford of the British Arachnological Society, speaking to BBC Wildlife.
Most people would probably wake up if a spider crawled across their face, long before it reached their mouth, according to arachnologists. Bill Shear speaks from experience, having once woken up on a camping trip to find a daddy longlegs on his face (a leggy arachnid, not the crane fly Brits know by the same name).
Someone sleeping with their mouth open is likely to be snoring, and the vibrations would probably scare a spider away. Spiders may not be fans of a snorer, and our tips on snoring may help keep the bedroom a little quieter.
Nobody knows exactly where the eight-spiders’ claim began. For years, the story went that a magazine columnist invented the figure in 1993 to show how easily people believe “facts” they read online. Fact-checking site Snopes later revealed that the columnist, Lisa Birgit Holst, never existed, and that her name is an anagram of “This is a big troll”. The myth about the myth was a deliberate prank all along.
The spider claim was already doing the rounds in a 1999 list of trivia, and its true origin is still a mystery. The idea may have stuck around simply because it’s gross, surprising and easy to remember. Spider stories can travel fast. A 2022 study of online news stories about spider encounters and bites from 2010 to 2020 found that 47% of articles contained errors and 43% were sensationalist.
Jumping spiders appear to have a sleep-like state at night. A 2022 study found that they twitch their legs and move their eyes while hanging from silk threads, a little like REM sleep in people. Whether spiders dream is still unknown, though one of the researchers believes they might.
Arachnophobia affects roughly 3% to 6% of people, according to a 2021 study in Scientific Reports, which also suggests the fear may have started with scorpions. Babies as young as six months showed signs of stress at pictures of spiders and snakes in Max Planck Institute research. The researchers think the reaction may come from millions of years of humans and their ancestors living alongside spiders and snakes. Upbringing and past experiences may also play a role, according to the Cleveland Clinic. Our guide to calming anxiety at bedtime may help if spiders are on your mind at night.
Are you still afraid you might swallow a spider? Here are some spider-proofing tips to have a good night’s sleep without any creepy crawlies:
Read more: How to keep spiders out of your bedroom
