Written by: Mallorie Stallings
Updated March 5, 2021
Do You Actually Swallow Spiders in Your Sleep?
Few urban legends evoke nightmares like the one about swallowing spiders in your sleep. According to this common myth, people swallow eight spiders per year while sleeping.
Although this claim is often repeated, there’s no evidence to support it. In reality, basic facts about spiders make the truth about what happens during sleep less scary.
Spiders Keep Their Distance
Although many people find spiders to be terrifying, almost all common house spiders are solitary creatures (1) that avoid contact with humans. The truth is, humans are scarier to spiders than they are to us.
Spiders have little reason to be in our beds. There’s rarely good prey to find there, and our sheer size and movements during sleep are likely to scare them off.
Your Mouth Isn’t a Target
Most people sleep with their mouth closed, so in the unlikely event that a spider made it to someone’s face, it usually wouldn’t have an opportunity to enter the mouth.
If you sleep with your mouth open, the warm air of your breath, along with any noise from snoring, would likely deter a spider from coming near your mouth.
Actually Swallowing a Spider Isn’t Likely
Even if a spider made it near your open mouth at night, it’s highly unlikely that you’d actually swallow it.
There’s a strong chance you’d be woken up by the sensation of a spider moving on your face. In addition, it’s rare to unthinkingly swallow during sleep (2), so ingesting a spider accidentally is extremely improbable.
A Myth Without a Source
The lack of proven instances of people swallowing spiders at night raises the question of how the “statistic” about swallowing eight spiders per year even came about.
Not only would accidental spider-swallowing be incredibly difficult to study, but it’s hard to imagine who would pay to conduct such research or who would volunteer to take part in it. The lack of actual data might explain why variations of this myth are common, such as claims that humans swallow three spiders per year while asleep, or seven over the course of a lifetime.
In the end, there’s no source or science behind the urban legend. However, it is an indication that humans hold certain biases (3) that can lead to misinformation and false beliefs.
Sleeping Soundly and Spider-Free
All of the facts demonstrate that it’s exceedingly unlikely that you would swallow a spider during sleep. Although it’s not totally impossible, accidental spider-swallowing goes against all odds and certainly doesn’t happen multiple times per year.
The bottom line is, you shouldn’t worry about swallowing spiders at night. Instead, focus on creating a calming bedroom environment, so you can sleep more soundly.
- https://pubmed.ncbi.nlm.nih.gov/29104823/ Accessed on March 2, 2021.
- https://pubmed.ncbi.nlm.nih.gov/46823/ Accessed on February 18, 2021.
- https://www.sciencedirect.com/science/article/pii/S0079742115000341 Accessed on March 2, 2021.