23 fascinating things you never knew about penguins

World Penguin Day is coming up on April 25, and INSIDER has you covered with some fascinating penguin trivia.

From one-foot-tall blue penguins, the world's smallest species, to gentoo penguins, who can reach speeds of 22 miles an hour in the water, these black and white avians are as interesting as they are adorable. 

Here are 23 fascinating things you never knew about penguins. 

SEE ALSO: 15 things you never knew about the animals that live in the Arctic's extreme conditions

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