

A tooth that senses the sea
The Unicorn of the Sea
A narwhal's long, spiraled tusk isn't a horn at all — it's actually a giant tooth, longer than a grown-up is tall, packed with nerve endings that can sense the water around it.
Diet
Eats other animals.


A tooth that senses the sea
A narwhal's long, spiraled tusk isn't a horn at all — it's actually a giant tooth, longer than a grown-up is tall, packed with nerve endings that can sense the water around it.


A pouch of his own
A daddy seahorse carries the eggs in a pouch on his belly and gives birth to the babies himself.


Floating together
Sea otters often hold paws while they sleep, so ocean currents don't drift them apart from each other.


One eye on watch
A dolphin sleeps with only half of its brain at a time, keeping one eye open to watch for danger.


Quiet flyer
An owl can swoop onto a mouse in almost total darkness without making a single sound, thanks to wings built for silent flight.


Hidden warmth
Under all that white fur, a polar bear's skin is actually jet black.


Chasing endless sunlight
Every year, a small Arctic tern flies from one end of the Earth to the other and back again, farther than one full trip around the entire planet.


Tiny builders
A giant coral reef is built slowly over hundreds of years by animals smaller than your fingertip.


Backward grower
One tiny jellyfish can grow younger instead of older when life gets hard, essentially reversing its own aging.


Extra beats
An octopus has three hearts, and one of them stops beating every time it swims.