What causes drumlins?

Drumlins are elongated, streamlined hills formed by the movement of glacial ice. They are created as glaciers advance, shaping subglacial sediment and debris into a teardrop or boat-like shape. The orientation and form of drumlins are influenced by the direction of glacier flow, and they often consist of till—a mix of clay, silt, sand, and boulders. Their formation typically occurs beneath the ice, as the glacier reshapes the underlying landscape.