Their neck is very flexible, so that the head can turn 180 degrees,[6] which gives them a broad field of vision which is helpful in locating prey; they also have highly mobile ears that allow them to track insects as they hunt. Round flat pads on their fingertips, between their fingers, and on their palms at the base of their thumbs enable them to firmly grip the branches.[7] They also have pointed, keeled nails that give them stability as they cling to smooth tree surfaces and reach for insects into crevices, using their rough narrow tongue.[8]