Today is World Penguin Day.

Yes, really: there's a whole day dedicated to celebrating those adorable little critters. The day is meant to be an educative initiative with the aim of encouraging people to learn more about penguins, their environment and just generally their imprortant to the ecosystem. It's also a few days past the Bank Holiday weekend, which means it is that point in the week where it feels like the days are just dragging by. So, to brighten up your Thursday - and because, like we said, it's World Penguin Day - we've rounded up eight facts about penguins you may not have known (and some adorable penguin photos to go with them).

There are 17 species of penguins.

The tallest is the emperor penguin, who stand at nearly four feet tall.

And the smallest is the little blue penguin, which is about 16 inches.

Penguins are black and white to help them camouflage: when seen from above, their black backs blend into the ocean; when seen from below, their white stomaches are hidden against the light.

Penguins ingest a lot of seawater while hunting for fish. It gets filtered from their bloodstream by the supraorbital gland, located behind their eyes. They get rid of the sea water through their beaks or by sneezing.

Penguins go a 'catastrophic molt', meaning they most all at once, spending two to three weeks land-bound.

Even though they don't have visible ears, penguins actually have pretty excellent hearing. They rely on distinct calls to find their mates when they return to the crowded breeding grounds.

There's a king penguin in Edinburgh Zoo who  was knighted by the King of Norway in 2008. Sir Nils Olav was promoted to Brigadier in the Norwegian Guard in 2016.