Water strider (Gerridae)

These insects are spectacular to observe. They are gliding on water surface, preferring calm waters, of course. But how do they do it?

This photo shows nicely that the surface of water is curved on all 6 points where the animal is touching it. The 6 dark dots are shadows of those curvings. They distribute their weight carefully on all 6 points, but this picture shows that the rear legs are touching water surface on larger area, not only at their tips. That creates enough surface tension to float. Rear legs are used more or less for floating and navigating, while very fast movements ahead are provided by front legs.

And there is more. When you read more about these animals, you learn that their legs are covered by thousands of tiny hair per milimeter. That results in small air bubbles, helping them additionally to float. Even if due to turmoil they get under water, due to that air they immediately float on surface.