Many pond insects seem to walk on water. They do so because of the surface tension. The pond skater’s legs press into a kind of elastic skin on the surface of the water but don’t go through!
Water acts different at the surface. Water molecules are attracted to each other and like to stay together, especially on the surface where there is only air above. The attraction between water molecules creates tension and a very delicate membrane. Water striders walk on this membrane.
Water striders are about a half-inch long with a thin body and three sets of legs. The water strider’s secret is its legs. The legs have tiny hairs that repel water and capture air. By repelling water, the tiny water striders stand on the water’s surface and the captured airs allows them to float and move easily.
The water strider’s shorter front legs are used for catching and holding onto food. Water striders eat insects and larvae on the surface of water, such as mosquitoes and fallen dragonflies.
Credit : National Wildlife Federation
Picture Credit : Google
