Very many things are poisons, but not all poisons are equally harmful to different organisms. A substance that is extremely harmful to insects, for instance (py

Very many things are poisons, but not all poisons are equally harmful to different organisms. A substance that is extremely harmful to insects, for instance (pyrethrin), is not very harmful to mammals, particularly humans. Even within mammals, there are differences: chocolate is toxic to dogs and cats, but considered a delicacy by humans and the main adverse effect is excess energy content.