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Practice English Speaking&Listening with: How Do Alligators See In The Dark?

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The dark is a scary place.

There are all sorts of wild animals lurking here.

Leopards, vampire bats, hyenas...

Wolves, Tasmanian devils, sea cucumbers...

And guess who else can see you at night?

And I mean like really well.

[terrifying whisper] Alligators.

[screams]

Down in the midnight swamps of the south, something is on the move.

But dont worry, it's only like TWO MILLION ALLIGATORS.

Alligators are highly adapted to low light and just nasty conditions.

For scientist like James Nifong, the alligator's hunting success is all down to its eyes.

These creatures have insane night vision.

James' BFF Dr. Kent want to know how on earth they do it.

So they're using the severed head of a deranged snapper that was formerly a threat to humans,

to study how its eyes are all the better to eat you with.

[James Nifong] "So the head from a big nuisance alligator, probably like 11 foot,"

"and we're going to dissect the eye."

Ewwwww, grossss!

Look away, Grandma.

Okay, so Kent dissects the eye - look at his face, this fruit cake loves it!

I'd say don't do this at home. but I'm gonna go and guess

your Mom doesn't have an alligator head in her kitchen cupboard.

[Dr. Kent] "Ahhh, those are the actual grinding crystals that are separating."

These precious little reflective crystals behind the retina bounce light around the eye.

The same crystals are found in sharks and some deep sea fish.

[voice of shark] "I'm watching you with my eye crystals."

[voice of small fish] "Me too Sharky, I'm reflecting like crazy!"

[James Nifong] "These crystals just act like a mirror, right?"

[Dr. Kent] "Exactly.

"It's reflecting all the light that comes through the eye, through the retina, right back through the retina.

It's basically as if there's twice as much light there as there really is."

Okay then rocket ship, so what happens when there's literally no light at all huh?

Like in the murky waters of a swamp.

[Dr. Kent] "Grab that gator skull behind you there and we can see there that the skulls are very ornamented in alligators.

But you see especially around the margins here, all these little pits and crevasses and canals."

Everyone of these holes contains a link to the alligator's nervous system.

[Dr. Kent] "Their entire head is covered in sense organs, which create this nerve net around the head.

They can feel any little impulse, any little wave in the water."

So basically this thing can see everything and when it can't, it can still feel everything.

It's like my Dad with his wallet, seriously.

[Dad voice] "Heyyy get your hands off my damn wallet".

To demonstrate this theory, the guys need a live predator.

[Dr. Kent] "This black caiman is a South American species with very large eyes.

It's actually the largest eyes of any crocodillian."

The incredible eyes of a perfectly developed killer.

With a room completely, totally blacked out, an infrared camera reveals them tempting a Philippine crocodile with fresh prey.

In these conditions, a human would see nothing at all,

and would probably feel a little weird being in a pitch black tank full of fish water.

[Jame Nifong] "She has it, she keyed in right on it as soon as I touched the water".

Basically guys, you're on the menu of two million gators and there is no where you can hide.

Okay, actually it's lucky you're not a fish, turtle, rat or raccoon, which make up most of the gator's diet.

And really, most gators are pretty weary of humans, especially when we wear shoes made out of their skin.

[gator's voice] "Hey where did you get those shoes from dude?"

[man's voice] "Your Momma!"

[gator's voice] "Huh, I'm feeling pretty wary."

Actual attacks are quite rare. In Florida, there's been about twenty fatal attacks in the last forty years.

And the most dangerous animals in the US are actually in your back yard.

About thirty Americans a year are killed by pet dogs.

And the deadliest animal of all?

Bees, which kill over 50 Americans a year.

My God!

[gator voice] "I'm innocent!"

The Description of How Do Alligators See In The Dark?