Almost all animals have ways to ward off potential predators, even the most ordinary species has their ways in dealing a good job in preventing others who not only wanting to kill them but eat them as well. A good example of these simple harmless looking animals are toads. Toads specially the king frog in our backyard secrete a poison from their skin. The glands which emit the poison are located all over the body, but are most concentrated around the neck.
Toads have poison sacs behind their eyes, and should a predator grab the toad, the toad will emit the poison into the animal's mouth. The taste from the poison is so bad tasting that 99% of animals will drop the toad when poisoned. The toad can then hop away to safety.
The totally bizzare case about frogs is that it is associated with the aztec's. In recent excavation, the aztec excavated sites have showed they have found hundreds of frog bones burried underneath the grounds. It was then believed that they drug the human sacrifice using the frog's poison before slaying them for the ritual offering to their hideous Gods.
It is mostly alarming that most people doesn't even know and realize the danger of these tiny littly creatures. Children play with frogs and most parents only think its hideous and dirty. But be warned nevertheless that as tiny as it looks its the size of potential damage it can bring.