When summer nears its end in Antarctica, emperor penguins bound out of the water and gather together to begin a long march. They march to their nesting ground 100 miles away. When they arrive, each penguin chooses a mate and starts a family. As winter descends and the sun goes down, the penguins huddle together against the cold and wait. Finally, in the middle of the frigid winter, the females begin laying their eggs. When the eggs are laid they are gently passed to the fathers. The mothers then leave for the sea to eat and bring food back for their babies. While the mothers are away winter begins its retreat, light returns to Antarctica, and the eggs begin to hatch. The babies are hungry, so while they wait for their mothers to return, the fathers release a milky substance from their throats and feed it to their newborn chicks. Finally, the mothers return to feed their babies, and the fathers go off to the sea to feed themselves. As the weeks go by, the parents take turns going back and forth to the sea to keep their babies full. The chicks spend more time together and grow stronger each day. In December, the middle of summer, the chicks are almost grown and they are ready to head to the sea. Once they are there, they plunge into the water and go home for the very first time. They spend four years living at sea, but when the warmer days begin to cool in their fifth year, they know it is time to begin their march, start their own families, and bring new life to Antarctica.