You Swallow Eight Spiders a Year in Your Sleep

There's no research behind this one at all, and the exact number, eight, has no traceable scientific source. The claim seems to have spread through 1990s trivia culture, including an appearance as a "Real Fact" on a Snapple bottle cap, and a widely reprinted 1993 magazine article that stated it as fact without citing any actual study. Once repeated enough times in classrooms, trivia games, and articles, it hardened into something that sounds like established science. It also runs against basic biology in both directions: spiders generally avoid the vibration, warmth, and breathing of a sleeping person rather than seeking it out, and there's no medical record of anyone regularly swallowing spiders in their sleep going back to check.