I love the shadow water striders cast at the bottom of a shallow stream. Water strider legs are covered with microscopic water-repellent hairs, which allow the striders to scamper across the surface of the water, using forelegs and hind legs for steering and middle legs for rowing. As though they were pressing down on a trampoline, each of the six legs distorts the water's surface tension, bowing the water down to create a concave lens that sends light waves into a bright ring and creates a dark lens shadow inside the ring. Fascinating!
