"The game of musical Shells.""A typical Black Friday Shells frenzy.""She swaps seashells by the seashore.""It's all a shell game, betting on which one is empty. Or it it more like a casino game of crabs craps?""Hermitage, sweet hermitage.""After observing this bartering of shells by crabs, Homo sapiens decided to stop bartering directly, and use shells as the medium of exchange."