Ratchet screwdrivers are a peculiar fruit which grow in a forest somewhere and are often used as primitive tools. Their life cycle is quite interesting. Once picked a ratchet screwdriver needs a dark dusty drawer in which it can lie undisturbed for years. Then one night it suddenly hatches, discards its outer skin which crumbles into dust, and emerges as a totally unidentifiable little metal object with flanges at both ends and a sort of ridge and a sort of hole for a screw. This, when found, will get thrown away. No one knows what it is supposed to gain from this. Nature, in her infinite wisdom, is presumably working on it.