“Humans swallow an average of eight spiders per year while sleeping”

The persistent notion that humans inadvertently consume several spiders annually during sleep is a widespread urban legend with no basis in scientific fact. This particular misconception is often traced back to a fabricated article from 1993, which supposedly aimed to demonstrate how readily people would believe outlandish claims found online. The article, intended as a prank to highlight the spread of misinformation, successfully embedded this unsettling image into public consciousness, where it has since taken on a life of its own.

From a biological perspective, the idea of spiders intentionally entering a sleeping person's mouth is highly improbable. Spiders are sensitive creatures that detect vibrations as a primary means of navigating their environment and hunting prey. A sleeping human, with their rhythmic breathing and beating heart, generates a constant stream of vibrations that spiders would perceive as a large, potentially dangerous animal. Far from being an inviting entry point, a person's mouth would be actively avoided by a spider seeking shelter (Review) or food. Furthermore, a human mouth provides no incentive for a spider, as it offers neither a suitable habitat nor a food source.

Despite its lack of scientific foundation (Review), this myth endures due to several factors. Many people harbor an innate fear or aversion to spiders, known as arachnophobia, which makes the idea of unknowingly ingesting them particularly unsettling and memorable. The "ick" factor associated with the thought of creepy crawlies entering our bodies while we are vulnerable in sleep contributes to its stickiness. Additionally, sensational and bizarre claims, especially those that play on common fears, tend to spread rapidly through word-of-mouth and online platforms, making them difficult to dislodge from popular belief once established.