One of my favorite comic strips is the usually funny and occasionally disturbing Pearls Before Swine. Yesterday the resident bad guy (aptly named Rat) is singing the John Denver song “Country Roads”. When asked what he is doing Rat answers that he is planting “earworms”. An earworm is a term for a portion of a song that becomes “stuck” in your head and you cannot get it out of your mind. Soon you are literally out of your mind. A survey of several hundred students came up with a list of the most insidious earworms.