(Intro)

Nature can be pretty weird sometimes.  You might already know about some animals that are, well, a little unusual, like the anglerfish, with the light dangling from its head, or the octopus, with its eight long tentacles, but one of the weirdest creatures on Earth is the narwhal, and I bet you can guess why.  Right on, Squeaks, narwhals are known for that long thing sticking out of their heads, called a tusk.  Some people even call them the unicorn of the sea, because even though unicorns don't really exist, the way narwhals' tusks stick out of their head makes it look a lot like a unicorn's horn.

A narwhal's tusk definitely looks strange, but what's even weirder is how it grows.  Tusks are basically very long teeth, so long that you can see them even when the animal's mouth is closed.  You might know of some other animals that have tusks like elephants and walruses.  What's different about a narwhal's tusk is that it doesn't grow out of the animal's mouth.  Instead, the tusk grows through the narwhal's head.  

The tusk starts out small like a normal tooth, but as the narwhal gets older, the tusk starts to grow bigger until it's touching the animal's lip, and then it just keeps growing, going all the way through to the other side.  It's almost like the narwhal is getting a mouth piercing, except instead of jewelry, it has a giant tooth.  

Now, not all narwhals have tusks.  All the  male narwhals have them, but only a few females do.  In many other types of animals that have tusks, both the males and females have them.  The narwhal's tusk also looks very different from other animals' tusks.  For one thing, they only have one tusk, while other animals usually have two, and if you put an elephant's tusk next to a narwhal's tusk, you can see that the elephant's tusk is a little curved and looks smooth on the outside.  On the other hand, a narwhal's tusk is straight and has a shape that's kind of twisty looking.   You're right, Squeaks, it does look a little like soft serve ice cream, but a narwhal's tusk definitely would not make a tasty snack.

Between the way a narwhal's tusk grows and what it looks like, it sure is different from other animals' tusks, but the tusk is also special, because it's so useful.  A narwhal can use their tusk to sense the ocean around them, a little like how you use your sense of touch to sense the world around you.  If you take your finger and gently tap on your front teeth, you'll notice you can feel yourself tapping them.  Since a narwhal's tusk is basically a giant tooth, scientists think that they can sense things in the water using their tusks, but what they're trying to sense and the exact ways that they use their tusks in the water are actually kind of a mystery.  

Why?  Well, it's really hard for scientists to learn about narwhals, because narwhals are super shy and they like to spend most of the day making deep dives into the ocean, so it can be hard to even see them, let alone study them.  Plus, they live way out in the Arctic Ocean by the North Pole.  The North Pole's cold and icy weather also makes it hard for people to study narwhals, so scientists don't know all of the ways narwhals use their tusks to sense the ocean around them, but they do have some good ideas.

For example, scientists discovered that two narwhals will sometimes touch tusks, so they think that narwhals can use their tusks to talk to each other, and not too long ago, scientists saw some narwhals using their tusks to help them get food.  They were bopping fish with their tusks so they were easier to catch and eat.  So scientists think that narwhals use their tusks to feel things in the ocean around them, to talk to each other, and to catch fish, but we still have a lot of questions, like what narwhals are saying to each other when they touch tusks and why only some female narwhals have them and whether they use their tusks for anything else.  

I know I can't wait until they figure out the answers.  Thanks for joining us.  Do you have any questions about your favorite animal or about anything at all?  Ask a grown-up to help you leave a comment down below or send us an email to kids@scishow.com.  Thanks, and we'll see you next time here at the Fort.

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