a sign that a woman was a witch. it was standard practice during the witch hunts in europe and the americas to strip the accused during an arrest and interrogation, and search her body for any suspicious-looking marks. moles, warts, birthmarks and scars were often mistaken for witch's tits; sadly, these alone were often all the 'evidence' needed to condemn the accused.

once a suspicious mark was found, it was pricked with a bodkin (witch pricker). if the mole bled, the accused was human. if it did not hurt, the woman was a witch. and yes, some witch finders used retractable bodkins so that they could collect more "bounty." it's a wonderful world.

why were extra nipples a sign of being a witch? it wasn't just because of the obvious freakishness factor. in those days witches were thought to be handmaidens of the devil. the devil in turn would send them animals, called familiars, to protect and serve them. most familiars would suck on extranummary teats present on the witch's body, presumably for nourishment.