Pins are used in both magic and Witchcraft, especially in ancient days. Pins are employed in casting magical spells and sympathetic magic. According to superstition, stray pins should never be left laying around because it is said that Witches gather them to use in magic. Medieval Witches supposedly used crooked in their brews to cast evil spells as well as to break them. Accordingly, Witches, to bless friends with happiness and prosperity, would pick a lemon at midnight and recited proper invocations as they stuck various colored pins into the fruit; to cast an evil spell or curse on an enemy they recited different invocations while sticking more black pins among other colors in the fruit.
In Witchcraft trials of the early centuries, pins were used to prick people, especially women, to locate what were called Devil’s marks, insensitive spots to pain, upon the body. Such marks, it was ruled, indicated that the person was a witch.
According to English lore, a Witch’s power could be destroyed by pricking a pigeon with pins or by sticking pins into the heart of a stolen hen.
While in instances of demonic possession, pins are frequently vomited by victims, along with other strange objects. (see Allotriophagy) A.G.H.
Guiley, Rosemary Ellen.The Encyclopedia of Witches and Witchcraft. New York: Facts On File.1989. pp. 269-270