1. Penguins （order Sphenisciformes, family Spheniscidae） are a group of aquatic, flightless birds living almost exclusively in the southern hemisphere.

2. They are highly adapted for life in the water, with countershaded dark and white plumage, and their wings have become flippers.

3. Most penguins feed on krill, fish, squid, and other forms of sealife caught while swimming underwater.

4. They spend about half of their life on land and half in the oceans.

5. Although all penguin species are native to the southern hemisphere, they are not found only in cold climates, such as Antarctica. In fact, only a few species of penguin live so far south.