Double, double, toil and trouble;
Fire, burn; and cauldron, bubble.
Shakespeare’s witches open Macbeth by tossing a toad into their cauldron, along with parts of snakes, newts, bats and other dejected, unfortunate creatures. Why such a bad rap? After all, people LOVE frogs – they turn into princes and are considered quite lucky by some cultures. But toads? Feared, reviled. What’s the big difference?
Toads (like the American toad, Bufo americanus, pictured above) tend to live in drier environments than frogs. In the frog’s aquatic environment, escape is just a hop away. For toads, though, warts are the key to survival. The two large “warts” on a toad, just behind the head, are glands that secrete a substance toxic to the toad’s predators.
But there’s the rub — Toads are associated with poison. They actually produce three kinds of toxins: two affect the heart and one can produce hallucinations. Some cultures have used these chemicals for medical purposes. Perhaps those Shakespearean hags were just brewing up a treatment for edema.