How do insects know when it's time to take a bath? When their feet get dirty and lose their stickiness! Insects depend on their adhesive footpads to help them travel safely on leaves, along braches, even over craggy rocks. A new study of the behavior of beetles found that when they start to slip, they know it is time to stop and groom themselves! Leaf Beetle photo: S.N. Gorb, University of Kiel, Germany