Look at this thing.

Isn't it amazing looking?

This is an Atlantic horseshoe crab, and they look almost prehistoric.

Which makes sense because they've been around for hundreds of millions of years.

But although they're called crabs, they're not actually crabs.

So what are they?

Why are horseshoe crabs called horseshoe crabs if they dont look like crabs?

That's right.

Despite their name, horseshoe crabs aren't really crabs.

Theyre more closely related to scorpions and spiders.

Let's take a look at one up close.

It has a hard outer armor.

The exoskeleton.

They molt this shell more than a dozen times over the course of their lives as they grow bigger.

The big part that looks kind of like a horseshoe holds the brain, The heart, and all the other important parts, including the largest set of eyes.

This small triangle in the middle is the abdomen, where their gills are.

And this long tail looks kind of scary, but don't worry, it can't sting you.

It actually helps the horseshoe crab flip back over if it lands on its back.

Every spring, horseshoe crabs mate and then come up at high tide to lay eggs about 5 to 10 inches deep in the sand.

females can lay about 80 to 100,000 eggs per year.

the eggs laid by these females won't all survive, theyre are really important food source for a lot of coastal birds, but the ones that do will make their way back into the sea, live for maybe 10 or 12 years, and then come back when they're adults to spawn on these very same beaches.

And these adults may live up to 20 or even 30 years.