A very varied family divided into a number of subfamilies:

Crambinae (the grass moths) with long narrow wings usually with longitudinal white or pale streaks which rest cryptically head downwards on grass stems from which they can easily be disturbed in the day. Their larvae feed in the rootstocks of grasses and sedges.

Acentropinae the China Marks and Water Veneer whose larvae feed in or under the water surface on aquatic plants.

Schoenobiinae are larger elongate moths whose larvae feed in the stems and shoots of reeds, sedges, grasses and bur-reeds in aquatic habitats.

Scopariinae are very similar looking species with short broad greyish forewings. They rest on tree trunks, rocks and walls from which they can be disturbed in the day, often flying back again if not alarmed, when they dive down into nearby grass and vegetation. Larvae of some species feed on mosses, some on roots and stems of herbaceous plants and decaying leaves, and some on lichens.

Glaphyrinae are broad winged pale ochreous to yellow moths whose larvae feed on Cruciferae.

Pyraustinae have triangular broad wings, some brightly coloured and marked with purple and yellow, and many are active by day and fly in sunshine.

Spilomelinae are the archetypical Pyraloid moths, resting with their broad triangular wings forming an arrow shape with projecting palps. Their larvae mostly feed on herbaceous plants. They include many migrant species to the U.K.