Ever heared of the French nuns that caught a case of mass hysteria and started meowing like cats? I'll quote a section about it on Wikipedia:

In The Epidemics of the Middle Ages, an 1844 collection of works written by J. F. C. Hecker (and translated by Benjamin Guy Babington), a translator's note by Babington, citing an unnamed medical textbook, recalls the story of a nun who lived in a French convent during an unspecified time (presumably in the Middle Ages) who inexplicably began to meow like a cat, shortly leading the other nuns in the convent to meow as well. Eventually, all of the nuns in the convent would meow together for a certain period, leaving the surrounding community astonished. This did not stop until the police threatened to whip the nuns.