Nuns' Cat Imitation Plague (15th Century)

In the 15th century, nuns in France and Germany exhibited bizarre behavior, with some imitating animals like cats, dogs, and birds. In 1491, a nun in a French convent started meowing, leading her sisters to follow suit, creating a "cat imitation" plague. Soldiers outside the convent brandished rods and threatened the nuns if the behavior persisted, while similar epidemics were reported across various nunneries. While "demonic possession" was the contemporary explanation, the more likely cause was mass hysteria stemming from the repressive conditions in which the nuns lived.