1. Fill bowl with water. 2. Place the cardboard fish on water surface . 3. Put a drop of dish soap just behind the fish’s tail ; the fish swims away. Water molecules cling to each other so tightly they cause the surface of water to squeeze together and bulge upwards - like a bubble. When the soap is put onto the water, this bond between the molecules breaks so the rest of the water pulls the water that is not bonded away - taking the cardboard fish with it !