[♪ INTRO]
Hey there!
Squeaks and I have been learning about different ways that animals can sense the world.
That means they use different body parts to help them gather information
about the world, to help them grow or survive!
What senses can you name, Squeaks?
[Squeaks squeaks]
Oooh!
Yes, we hear with our ears, we smell with our nose…
and we see with our eyes!
[Squeaks squeaks]
Ooh, good question!
Squeaks wants to know if all animals sense the world like we do.
Many animals have very interesting senses.
Eagles have two eyes, just like we do.
But their eyes are much stronger than a human’s!
They can see more colors than people can.
And they can spot a rabbit from way up high in the sky when they’re searching for food!
Some animals’ eyes are even more interesting than that!
Let’s look at this picture of a spider!
Do you notice anything about it?
[Squeaks squeaks]
Ooh yeah!
We have two eyes, but this spider has eight eyes!
Since the spider’s eyes are different from ours, its sense of sight
is also a little different from the sense of sight most people have.
The eyes all around their heads are very good at seeing movement.
So it can help the spider spot something it wants to eat, like a tasty bug,
as soon as it moves!
[Squeaks squeaks]
Well if you think that’s impressive, some insects, like bees and dragonflies,
technically have thousands of eyes!
[Squeaks squeaks]
Right…
when we look at a dragonfly, we don’t see thousands of eyes.
It looks like they have two big eyes here and here.
But if we take a closer look, you’ll notice that each of these eyes are made of
thousands of smaller eyes bundled together.
Special eyes like these are called compound eyes.
[Squeaks squeaks]
Oh, good question, Squeaks!
Squeaks wants to know if they see lots of pictures at once…
like a wall of screens all showing the same picture.
Well, to answer that, let’s first talk about how our own eyes work.
Each of a person’s eyes has one lens.
That’s a special part of the eye that lets in the light that we see.
It helps make a sharp picture of the thing we’re looking at.
Then, the picture goes to our brain, which helps us understand what we’re seeing.
But in dragonflies, the top part of each of the smaller eyes inside
the compound eye is called a facet.
If we could look really closely at a single one of these facets,
we would see that every single one has a lens, and every one lets in light.
Each lens sends an image to the dragonfly’s brain,
where, they’re put together to make one picture.
[Squeaks squeaks]
Ooh yeah, it is a little bit like putting together a jigsaw puzzle.
Together, a bunch of small pictures make one bigger picture.
All of the parts of the compound eye help the insect to see.
Scientists think that the picture is kind of blurry, though…
and looks kind of like what happens when you zoom in too much
on a tablet or phone picture.
[Squeaks squeaks]
That’s a great question!
Squeaks wants to know: why do some animals have compound eyes?
It doesn’t seem to make sense, especially if the picture is blurry.
A dragonfly’s big compound eyes wrap almost the whole way around its head.
So it can see what’s going on behind it and in front of it… at the same time!
That’s pretty awesome for a few reasons.
First, it’s kinda hard to sneak up behind a dragonfly.
The picture from a dragonfly’s eyes might be blurry… but the insect
can definitely tell how big something is, and if it’s moving or not.
That makes a dragonfly pretty hard to catch for animals that might want to eat it!
Second, being able to see so much means that the dragonfly
is an excellent hunter.
A dragonfly can eat hundreds of insects every single night!
[Squeaks squeaks]
Yes, that was really interesting!
Hey… let’s SEE if we can find out some more cool facts
about how animals sense their world!
[Squeaks squeaks]
Thanks for joining us here at the Fort.
If you want to keep learning and having fun with Squeaks, me,
and all of our other friends, be sure to hit the subscribe button,
and we'll see you next time here on SciShow Kids!
[Squeaks squeaks]
[♪ OUTRO]