Penguins are flightless birds that live in packs in many parts of the Southern Hemisphere and swim using their wings at speeds up to 15 miles per hour. They mate for life, lay eggs, and may steal other penguins' chicks if they lose their own. Different types of penguins live in different areas depending on temperature, with some inhabiting extremely cold places and others closer to the equator, and they can be found on ice, beaches, or small islands near the ocean where they spend most of their time hunting for food underwater.