Water striders are also sometimes called pond skaters and that is actually a very suitable name for them. They move with quick, erratic actions, darting forward and then skating in place. Sometimes they jump in the air and land again without sinking.
They are exploiting the surface tension of water which is a thin elastic “skin” every liquid has. You can see the effect of surface tension when you see a drop of water close up. It looks like a little bead of water, a tiny dome. Surface tension is what makes the dome shape – the water doesn’t flatten out.
The common water strider (Aquarius remigis) has short front legs which are built for grabbing prey. The middle and hind legs are extremely long and covered in very fine hairs allowing the insect to rest and skate on top of water without breaking the surface film.
During breeding season, this species can communicate with potential mates by sending ripples over on the surface of the water. You should watch them for a while next time you see them on a pond.