Drumlins are elongated hills formed by the movement of glaciers. They are typically composed of glacial till, which is a mix of clay, silt, sand, and gravel. The shape of a drumlin resembles a teardrop, with a steep side facing the direction from which the glacier advanced and a gentler slope on the opposite side. These landforms are often found in clusters, known as drumlin fields, and can vary in size. Drumlins provide important information about past glacial activity and are studied in the field of glaciology, which examines the dynamics of ice and its effects on the landscape.