Any day with penguins seems rather happy to me but today's the official World Penguin Day! To celebrate the pretty black and white (and sometimes blue!) birds, check out the scoop about the 17 species of penguins worldwide. Many times, looking at their heads is the easiest way to tell them apart — makes sense because that's what we can see when they pop up from swim time — but see for yourself and get started.
Source: Jupiter Images