earwig

Earwigs are small insects that were once thought to crawl into the ears of sleeping people. This isn't true - earwigs prefer moist, dark places under leaves and rocks to human ears - but the superstition led people to name the insect ēarwicga, Old English for "ear insect." Over time, people connected the idea of having an insect in one's ear to situations that involve whispering or speaking privately into someone's ear. The noun earwig came to also mean "a whispering busybody" (though this sense is now considered archaic), and the verb earwig evolved to refer to the acts of such meddlers. In British English, the word is more commonly used to mean "eavesdrop," as in "earwigged on their conversation at the party."