Get hands-on with physics and engineering by constructing eight awesome walking machines! Explore the workings of gear trains, linkages, and non-circular gears as you create complex walking devices. Each model moves in a different way. For example,the four-legged terrain-walker bot keeps its body level as it moves step by step, while the kangaroo-bot hops forward on two legs. The leopard-bot has four long legs while the wild boar has four short legs. The fairy shrimp model wriggles along on swimmerets while the monkey model uses its arms to crawl along a string.