Drunella cornutella prefer riffles with medium to fast water currents. Even though hatching occurs at different times of the day, Drunella cornuta mornings, Drunella cornutella afternoon, and evenings. Their hatches may also overlap during cloudy cool days. Cornutella is easily confused with cornuta when observed on the waters surface because of their closeness in size and color. Freshly hatched duns of cornuta are yellowish olive, but as they float along the surface quickly change color eventually becoming darker, similar to cornutella. Taking a closer look at the two insects you will find that cornuta's legs are yellowish olive when freshly hatched, becoming light olive as the insect darkens. Cornutella's legs on the other hand are much darker, and display an almost black color on the upper side of their legs in the femur section.