Humpback Whales are carnivores that filter feed krill, plankton, and small fish like herring, mackerel and sandeel. Each whale eats 1 to 2 and 1/2 tons each day during the 120 days of the feeding season. To obtain this amount of food, they feed twice a day. About 25% of what they eat during the feeding season is stored in a form of fat to provide in making extra energy and insulation during their winter fast when they migrate to warmer waters. Humpbacks have 270-400 pairs of dark grey plates hanging from each side of the upper jaw, where teeth might otherwise be located. The plates are black and 25-30 inches long and 13.5 inches wide. As they hunt, the members of a pod have developed a way of rounding up large masses of prey called bubble-net or bubble cloud feeding. In developing the method, the whales make a circle 50 ft under the water and 10-100 ft across. Beneath the fish, they blow bubbles in a cylindrical wall which traps the fish making them swim to the surface. Now, the fish have no where to go and the humpbacks take their turns feeding on the large, tasty meal.