Some animal life forms can imitate their surroundings closely to protect themselves against predators - think, for example, of the caterpillar which looks like a piece of twig. We call this act of copying "mimicry".

The aim of the game is to try to move each of the 33 clam shells onto a vacant square on the board and then turn it over. 

Your game is over as soon as you have turned over all the shells. If you reach a stage in the game where, following the moves allowed, you are unable to move any more shells onto vacant squares, the game is also over.