Rats and mice once were considered to be among the leading familiars of witches. Seventeenth
century Quakers called rodents “the devil’s disciples” and said that they were carriers of the devil’s lies and deceits. A house or ship infested by rodents had to be exorcized, according to Quaker belief. The method was to write a stern letter ordering them to leave under threat of death.
Supposedly, the rodents would find it, eat it and then leave. It was necessary for them to eat the letter in order to understand it. A 19th-century rat Exorcism letter found in the cellar of a Quaker home in Cape Cod, Massachusetts, calls the rats “spirits of the bottomless pit” and warns,
“Begone, or you are ruined! We are preparing water to drown you; fire to roast you; cats to catch you; and clubs to maul you.”
The letter then instructs the rat to go to a neighbor’s house. In other lore, rats are said to be the embodiment of evil spirits and will haunts houses. Since ancient times, rats have been associated with the human soul. Their sudden disappearance from a ship or a house forewarns of death, doom and disaster.
Cahill, Robert Ellis. Strange Superstitions. Danvers, mass.: Old Saltbox Publishing, 1990. radford, E. and m.A. The Encyclopedia of Superstitions. Edited and revised by Christina Hole. New York: Barnes & Noble, 1961.