In the infamous Witches’ Song in Macbeth the first verse goes…
Double, double toil and trouble;
Fire burn and caldron bubble.
Fillet of a fenny snake,
In the caldron boil and bake;
Eye of newt and toe of frog,
Wool of bat and tongue of dog,
Adder's fork and blind-worm's sting,
Lizard's leg and howlet's wing,
For a charm of powerful trouble,
Like a hell-broth boil and bubble.
But why are snakes and news and frogs and bats and dogs and lizard’s so powerful when it comes to witchcraft and witch lore? Well, I can’t answer all of those questions just yet...but how about we start with bats?
One of the most obvious connections between bats and witches is that, largely, humans are afraid (or at least wary of) both. Furthermore, both bats and witches are capable of flight. Bats were often compared to rats or referred to as flying rats. Rats were known for spreading disease and pestilence, and, like witches with their power to create evil, were feared. Thus, a flying rat was likely to be considered more like a witch than many other animals. The pervasiveness of bats and witches in culture has stood the test of time and seems as relevant (if not as serious) today as it was hundreds of years ago.
In addition to black cats and toads, bats have often been depicted as familiars of witches and, in some cultures, witches have the ability to transform into bats (similar to vampires). They make particularly interesting creatures to turn into because of their nocturnal nature and ability to fly in the dead of night. In fact, in the infamous ‘flying’ ointment, bats’ blood is a major ingredient.
However, it would be unwise to pigeon-hole bats as being used as ingredients or elements of witchcraft for only negative uses. For the same reasons bats make good familiars, their blood, excrement, and wool are also powerful in folk potions that are said to aid vision, cataracts, and more. In addition to sight-aid, bat ingredients were often popular in sleeping-draughts and to help sleep issues. One would think a nocturnal creature’s elements would not be as helpful in these situations, but here we are.
It seems that bats are often in spells and witch lore because of their similarities to actual witches. In addition, their ability for flight, strange appearance, and nocturnal behavior seems to link them with evil and being closer to the veil. Their unique physical qualities, like echolocation, flight, and communication also make them useful in spells and folk healing which typically include ingredients from animals and nature that reflect what they are trying to accomplish in the greater world.
The above image is from Flickr User Daniel Spiess and is licensed under Attribution-ShareAlike 2.0 Generic (CC BY-SA 2.0)