The water measurers, or marsh treaders, look similar to stilt bugs but they live in completely different habitats. These dark brown insects can be found along the shores of ponds and small creeks, where they walk methodically over vegetation and the water surface. They are only about 7 mm long and extremely slender; their dark color makes them difficult to see against floating plants such as duckweed. The head is quite long, with the eyes placed midway down its length. Hydrometrids are predators and scavengers, often seen feeding on dead insects that have drowned in the water.