There are 18 species of penguins, primarily found in the Southern Hemisphere. The most well-known species include the Emperor Penguin, the largest, and the Little Blue Penguin, the smallest. Other notable species are the Adélie Penguin, Chinstrap Penguin, and Gentoo Penguin, each adapted to their unique environments. Penguins are flightless birds, relying on their strong flippers for swimming. They are excellent divers, with some species capable of reaching depths of over 500 meters. Penguins primarily feed on fish, squid, and krill, and they often form large colonies for breeding and protection against predators.