BBC news has an article that explains how a robot insect walks on water. MIT professor, John Bush, and his fellow researchers have figured out that water striders (aka water skeeters) walk on water by utilizing the surface tension of the water to float and by sculling (rowing) across the water. He tested his theory by putting together a tiny robotic test bed called the Robostrider to prove his point and it worked. The Robostrider can also float on water and row just like real striders. Apparently, the skeeters create tiny vortex waves and are able to push quickly yet carefully against these water vortex waves without breaking the surface tension of the water. The MIT researchers have found that the water vortex sculling is the most efficient method of locomotion on water.