Water striders walk on top of the water by using the surface tension, and they also have hydrofuge hair in their legs. Water striders are dark brown or black, and about one centimeter long. Some have long or short wings while others have no wings. The individuals with long wings are able to fly. Water striders are predators and feed on other insects.

Most of water striders are freshwater species, but there are some marine species as well. They are often found as large groups near shores and they thrive in places where there are a lot of other insects. Water striders have a broad area of distribution including Eurasia, North and South America, South Africa and Australia.

Water striders might indicate water quality since e.g. detergents that weaken surface tension can sink them.