 The challenge posed by the puzzle is how to release the sphere (the hedgehog) from the cylinder (the cage).Although known mainly through the children's stories written by the Czech Jaroslav Foglar in the 1940s, Hedgehog in the Cage has its origins in the United States.The first known model of the puzzle was patented by the American inventor Clarence A. Worrall in Philadelphia, Pennsylvania, on 7 April, 1896.