Adult caddis flies are found in both still and moving water. Adult caddis flies is most common to find on the water during the time when they hatch or the female lay her eggs.
Most adult caddis flies have a dark colour. The wings are either spotted or coloured in the same colour as the body. When they move across the surface after they have hatched or lay their eggs, they often do it with impressive speed. They almost look like small racing boats. An egg laying caddis is usually harder for the fish to catch then a new hatched one.
Just as with the largest mayflies, a hatch of large sized caddis flies will attract big fish to feed in the surface.