Walk on Water
How does the water strider stay on top of the water?
- Water striders have hydrophobic hairs on their body, including their legs. They have about 1000 microhairs per millimeter, providing resistance to drops of water, shedding the weight, keeping them light on top of the water, using surface tension to stay afloat.
- They have light, flexible, and strong legs, but also use their wide spread of legs to balance themselves, spreading their weight evenly.
- The hind legs steer, the middle legs propel, and the front are used for prey, all in balanced motion. The claws are positioned halfway up the front legs allowing the strider to maintain water contact even when it has punctured and eating smaller prey.
- The microhairs trap air bubbles so even if it is partly submerged, it maintains buoyancy.
- The middle legs perform a circular rowing motion, creating a surface wave which it rides. It can move at 1m per second, using a coordinated rowing motion.
- The water striders feed on other insects, using wave/ripple sensors in its front legs.
As a child, I was fascinated by water striders (the interest still remains after decades.)