Strange behaviors and illnesses in students are examined through the centuries. Possessed children went into trance states and began to bark like dogs in 16th and 17th century Holland; an epidemic of twitching, trembling and blackout spells swept through European schools during the latter 1800s; an outbreak of Tourette's-like symptoms struck schoolgirls in western New York in 2011-12. In addition to the US and Europe, separate chapters detail accounts from Asia, Africa, Latin America and Oceania. A variety of theories to explain outbreaks are examined.