While a popular urban legend states that adults swallow an average of eight spiders a year, there is almost no chance of this happening by accident. Spiders are not likely to approach the mouths of large sleeping predators, and while a random event is possible, it is statistically unlikely.
The original myth comes from Lisa Holst, who set out to demonstrate the gullibility of her audience during the 1990s. The so-called fact was immediately accepted and disseminated as a piece of trivia to scare and disgust people for decades. However, realistically, humans are so large in comparison to arachnids, that spiders view humans as part of the landscape. Sleeping humans also emit vibrations from snoring, breathing and drooling that translate to spiders as signs of danger. The lips and tongue are also extraordinarily sensitive, and a spider dropping or crawling into the mouth is likely to alert and wake the sleeper.
While accidental ingestion of spiders is rare, a region in Cambodia regards fried spiders as a delicacy, popular among tourists. Its origins are a myth, but most believe the dish can be traced back to the Khmer Rouge regime and the prospect of starvation. The Cambodians fry a species of tarantula known as the a-ping, which is roughly the size of a palm.