To construct a raft, the snail sticks part of its muscular foot just above the water and cups the foot to enclose a pocket of air. Glands on the foot secrete a tacky mucus that quickly seals the air in a bubble. To make its float larger, the snail presses the newly created air bubble onto the existing cluster of bubbles, and as the mucus hardens, the bubble adheres to the rest of the “raft.” Part of the snail’s foot grasps onto the raft at all times, and the snail floats upside-down in the ocean.