[♪ INTRO]
Squeaks?
Hmmm. I don’t see him anywhere.
Oooh, maybe he’s… up here!
Hmm…
Oh, hey!
Squeaks and I were just playing Hide & Squeak.
That’s when Squeaks hides, and I find him, using my senses!
Senses are ways you experience the world,
like seeing, hearing, feeling, tasting, and smelling.
We use different body parts to use our different senses!
Ooh, maybe you can help me out!
Okay, let’s use our senses…
like hearing, or smelling.
Hmm… do you smell Squeaks anywhere?
Use your nose and tell me.
[Sniffs]
Hmm… no?
Okay, how about using your ears to hear.
Do you hear Squeaks?
[Squeaks squeaks]
You do?
Hey, yeah! I do, too!
I think it’s coming from over here!
[Squeaks squeaks]
Oh hey Squeaks!
That was a great hiding place.
And great job using your sense of hearing to find him, everybody!
You know, not every animal has the exact same senses you do.
Some fish, like sharks, can see and hear and smell, just like humans can.
But they also have a sense called electroreception.
[Squeaks squeaks]
Oh, well, let me try and explain by showing you a picture of a shark.
You remember how I said we use our body parts for different senses?
[Squeaks squeaks]
Well, do you see these dots on the shark’s face?
Those are the special body parts it uses for electroreception.
All animals make a tiny bit of electricity, just like the kind that turns on our lights.
If that sounds incredible to you, it's probably because you and I
can't feel the electricity animals make.
And that's because we don't have the right body parts.
But sharks have these special spots that let them sense electricity!
If there are animals nearby, like fish, the shark will know because these dots
on its face tell it when something electric is close by.
The special spots are called ampullae of Lorenzini.
And they pick up electricity, and send it through special tubes to the shark’s brain.
That tells the shark where the electric signal is coming from.
[Squeaks squeaks]
Oh!
Yeah, the spots are named after the scientist who discovered them.
His name was Stefano Lorenzini!
When you and I play Hide & Squeak, we use our senses of seeing and hearing...
and sometimes smell!
When a shark is looking for its prey, it uses its senses too.
While the shark is still far away from its prey, it uses its senses of hearing and smell
to locate a fish.
When the shark gets a little closer, it can use other senses, like sight,
to find the fish it’s hunting.
Then, when the shark is less than a meter from its prey, it uses electroreception
to figure out exactly where the fish is, and exactly how to aim its jaws to get a good bite.
And then…
it’s time for lunch.
[Squeaks squeaks]
Oh, it’s okay, Squeaks.
Sharks hunt for fish in the water, but they can’t come onto land,
and they aren’t usually interested in people, or robot rats.
We’ve never had a shark here in the Fort.
[Squeaks squeaks]
Oh, great question!
Squeaks wants to know, if sharks can see and smell,
why do they need electroreception?
Well, sharks can use their special spots to sense fish even when those fish
cover themselves in sand.
That means when they can’t see or smell the fish,
they can still find them using electroreception.
Scientists figured out that the ampullae of Lorenzini were helping the sharks
sense electrical signals from the fish.
So even though they were hidden, the sharks could still find them!
[Squeaks squeaks]
Oh yeah, I know, Squeaks!
A shark’s sense of electroreception is pretty cool!
I wonder what it’s like to be able to use electricity to experience the world.
[Squeaks squeaks]
I bet you’re right.
But I don’t mind finding my lunch the old-fashioned way.
Hey, what do you think we have in the refrigerator? I’m hungry!
[Squeaks squeaks]
Thanks for joining us today.
If you want to keep learning with me, Squeaks, and all of our friends,
be sure to hit the subscribe button, and we’ll see you next time here at the Fort!
[Squeaks squeaks]
[♪ OUTRO]