Do We Actually Swallow Spiders in Our Sleep?

According to spider experts, the odds of swallowing even a single spider over your entire lifetime are so low that they're virtually zero. It's extremely unlikely a spider would even willingly approach a sleeping person, much less crawl into their open mouth and wait to die.

A 1993 magazine article is probably responsible for spreading the idea that people eat spiders while sleeping.

In it, the author put forth the intentionally false fact that we swallow eight spiders every year in our sleep. The author was trying to make a point about how willing people are to believe something they read online, no matter how counterintuitive the information may be.

The irony is, people ended up believing the false fact about the eight spiders and have been perpetuating its circulation as a kind of urban legend ever since.

While one in five Americans admitted to a fear of spiders in a 2022 YouGov poll, spiders are actually much more afraid of you than you are of them.

Think about it: The spider uses vibrations to sense danger. A sleeping human is nothing but noise and vibration, from your breath and heartbeat, to tossing and turning, to snores, snorts and other sounds.

Everything about a human at rest signals for spiders to steer clear, giving them no incentive to creep into your bed during the night. Instead, they prefer to hang out in quiet, unoccupied parts of the home or spend their time tending to their webs.

Spiders have evolved to survive, not to crawl into people's mouths and die.

They thrive in diverse habitats, from arid deserts to damp forests, and are adept at conserving water, minimizing the loss of water vapor through their exoskeletons. Like all terrestrial animals, spiders breathe oxygen and exchange carbon dioxide with great efficiency, using structures called book lungs or tracheae.

Spiders rely heavily on their sensory hairs to interpret their surroundings, detecting the presence of other creatures and the composition of the air, including traces of carbon dioxide emitted by insects. This intricate perception of the world enables spiders to be proficient hunters and survivors in a variety of environments.

Spiders' experience of the universe is vastly different from ours, shaped by their unique sensory systems. With eight tiny legs, spiders navigate their environments with remarkable agility, whether it's the vast expanse of a forest or the confined space of a moist cave.

Spiders' sensory universe is dominated by vibrations and chemical cues rather than visual information, allowing them to detect the faintest movements, such as those of insects caught in their webs, and subtle changes in air currents, which could signal potential prey or danger.

But what if you were asleep and along came a spider whose ability to sense vibrations was a little off? Could this spider fall into your mouth accidentally? Sure, it's possible that a spider might fall or crawl into your mouth, but it's extremely unlikely, and here's why.

First, you'd have to have your mouth open fairly wide while snoozing, which is far from a universal trait. Next, you'd have to be able to sleep through the sensation of a spider crawling its way across your face and into your mouth.

Finally, you'd have to actually swallow while you're sleeping, which is not automatically going to happen without a little effort on your part. A spider would likely change its mind or get bored and crawl back out of your mouth before the stars aligned for all of these events to occur.

Still afraid to fall asleep lest you end up ingesting a spider or two? According to the Burke Museum of Natural History, you can relax. There's not a single reliable report anywhere in a scientific or medical source to prove that anyone has ever swallowed a spider while sleeping, much less eight per year.

You'll be glad to know that the odds of being bitten by a spider are also quite low. Despite their fearsome reputation, most spiders are not aggressive toward humans and will only bite in self-defense when they feel threatened or cornered.

Many species of spiders have fangs that are too small or weak to penetrate human skin. Additionally, it's easy not to notice spider bites or mistake them for bites from other insects. In general, the likelihood of experiencing a significant spider bite is minimal, especially if you take common-sense precautions.

If you're worried about these creepy crawlies, always shake out your shoes and clothing before wearing them and avoid reaching into dark, undisturbed places where spiders might be hiding.

We updated this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.