Drumlins are elongated hills made of glacial deposits. They are typically found in regions that were covered by glaciers during the last ice age.
Drumlins are formed as glaciers move over the landscape, picking up and depositing sediments. As the glacier advances, it deposits a mixture of clay, silt, sand, and gravel in the shape of an elongated hill or ridge. Over time, these deposits are shaped by the moving glacier, resulting in the characteristic streamlined, teardrop shape of drumlins.