Adults parallel sided, elongate, and soft-bodied (beetles have rather soft cuticle so that the body and elytra are much less rigid than in usual for beetles); 1-25 mm long. Elytra may not completely cover the abdomen although the wings may. Head protruding from flattened pronotum, generally visible from above. Labrum strongly reduced, usually membraneous. Antennae generally thread-like (filiform), rarely pectinate or flabellate, usually 11-segmented, with rare exceptions (not recorded from Borneo); eyes circular, always obvious. Tarsi 5-5-5, 4th segment lobed. Larvae tend to be dark brown or grey, slender and wormlike with a rippled appearance due to pronounced segmentation. most larvae are covered with dense bristles that make them look velvety.