"Intrigued by their observations, Bush and his two colleagues decided to mimic the animals’ motion by building a larger-than-life mechanical pond skater. Dubbed Robostrider, this beast isn’t as menacing as it sounds. Its 9cm (3.5in) body was made from aluminium cut from a fizzy-drink can, while its legs were fashioned from stainless-steel wire. The researchers powered Robostrider by running an elastic thread from a sports sock down the length of its body and connecting the elastic to each leg via a pulley. Weighing just 0.3g (0.01oz), Robostrider acted like a real pond skater. With its weight supported entirely by surface tension, this artificial creature moved forward, just like its real counterpart, by rowing its legs to make hemispherical vortices. It travelled about half a body length per stroke – roughly 18cm (7in) per second (about one-fifth the speed of a real pond skater). ‘It moved relatively clumsily, like a water strider wearing chain mail,’ says Bush. Though that’s not bad for a beast made from a sock and a fizzy drink can."