It can be 100 feet in length and weigh 120 tons. Like other mammals, baby whales drink their mother's milk, which is rich in vitamins. A baby gray whale may drink 50 gallons of milk a day and gain 200 pounds daily. Whales have special mouth parts for obtaining food. Others have teeth to catch and rip their food, which may consist of plankton, krill, or fish.
Plankton are microscopic plant and animal organisms floating in water in large numbers.
Krill are small crustaceans. Baleen whales usually do not go as deep as toothed whales because their food is near the surface. A baleen whale can gulp or skim krill from the water. Humpbacks are baleen whales. They spend three or four summer months off Alaska.