ELI5: Explain Like I'm 5

Dancing mania

Dancing mania was an event that happened in Europe hundreds of years ago. People in Europe began to dance uncontrollably in large groups for days and weeks at a time. They did this without any music and in some cases, until they fell down from exhaustion. Nobody knows why this happened, but experts think it was caused by a mix of psychological and physical factors like hunger, stress, and an illness that caused hallucinations.