This article was originally published on December 11, 2019.
You would have probably seen some insects like water striders moving on the surface of lakes, ponds and other water bodies. So, how do these insects manage to float on water without ever getting drowned?
These families of insects are known as Gerridae. They are also known as water skeeters, water bugs, water skippers, pond skaters, or Jesus bugs. Water striders are anatomically built to achieve this feat. They are built with elongated legs that aid them in this process.
Their whole body is covered with hydrophobic micro-hairs that are resistant to water drops and splashes. They just don’t sink in water. These tiny hairs trap air in between them and prevent water drops from weighing them down.
Surface tension in water
We know that water is made up of hydrogen and oxygen molecules. But water molecules that are on the surface of the water cannot just bond with the molecules in the air above.
So, water molecules at the surface form a strong cohesive bond between each other and act as the skin for the water. These cohesive forces are strong enough at its surface to hold small and light objects from getting drowned.
Water striders are light and they spread out their weight evenly with the help of their front and back legs. They user their middle legs to maneuver and skate on the water surface. With their micro-hairs, light bodyweight and the surface tension of water, water striders can easily walk on water without ever getting drowned.
Fact: Basilisk lizards can run on the surface water. Because of their super speed and specifically designed feet, they manage to quickly run across the surface of the water without getting drowned.