- [Instructor] Snakes are among the most efficient predators
in the animal kingdom.
It's not hard to see why.
Razor-sharp fangs, deadly venom, or powerful muscles
that will squeeze the life right out of its prey.
But tracking and catching prey in a dense forest like this
requires more than sharp teeth and some nasty venom.
It requires one of the best chemosensory perceptions
in the animal kingdom.
Snakes have perfectly good sight
but their sense of smell is so powerful,
their eyes are almost superfluous.
They have normal nostrils visible on their snout,
which work just fine.
But what they use to smell their prey
is actually their forked tongue.
(chirping)
As the snake flicks its tongue,
the tongue picks up tiny scent particles in the air.
Essentially it's tasting it's prey.
Then it delivers those particles to the vomeronasal organ
better known as the Jacobson's organ
which is located in the roof of the mouth.
The organ is completely separate from the nasal cavity
and operates autonomously.
Its role is mainly to detect pheromones from prey
and potential mates.
This corn snake has picked up the scent trail of a mouse
and closes in on its quarry.
As it analyzes the scent,
the snake can decrypt the species, size, and direction
of the prey's travel.
It knows exactly where the mouse is
and if he misses the first time,
he adjusts the strategy as needed,
and doesn't miss again.
A snake's nose does more than just smell.
Some snakes like pythons, boas and pit vipers,
have an astonishing sense
that gives them even more of an edge.
They can sense heat.
These snakes can feel the location of slight changes
in ambient temperature.
They can see the infrared heat waves of a living organism
using small nostril-like pits on their faces.
A blinded pit viper can sense a mouse
that is a mere 10 degrees Celsius warmer
than the surrounding air from 70 centimeters away.
This mouse's fate was sealed
long before the corn snakes fang sank in.
When the first of its heat waves
radiated across the forest floor,
and its scent particles
first landed on the snake's forked tongue.
Despite the prowess of their serpentine foe,
there are at least as many rats on the planet as people.
7 billion, probably more.
Rodents have found ways to survive and thrive,
thanks to their sense of smell.
This is the brown rat,
a fuzzy pet version of what's also known as the sewer rat,
Wharf rat or Norway rat.
Most live near food and garbage.
They've crawled and nod their way through every continent
except Antarctica.
Scrappy in their hunt for scraps,
rats keep their nose to the ground.
They've got three times more genes
that code for smell receptors, than people do.
That makes smell very important to them.
B.O is their ammo.
It's at the center of all their interactions,
and there are a lot of rat interactions.
They're social creatures after all.
A colony can host up to a 100 rats.
From a whiff of another rat's breath,
rats can tell where the nearest buffet is
and exactly what's on the menu.
Rats pick up each other's scent from urine
and other bodily secretions on the ground
and chemicals in the air.
Each rat's own smell is a unique cocktail.
Inside a rat's nose,
olfactory receptors scan another rats odor like a barcode.
Like their enemy, the snake,
they use a Jacobson's organ
that dense pack of sensory cells
above the roof of their mouth
to pick up airborne chemical signals.
All that chemical information
speeds to the brain for analysis.
There's no privacy.
One whiff and a rat can determine another rat's sex,
social status, stress level, and colony membership.
The next move, aggression, affection or attraction
is all based on that initial smell.
This guy can tell from her scent,
that the female is ready to mate.
He's picking up scent clues even if
she doesn't look like she wants to go through with it.
Rats noses have helped them go forth and multiply,
finding mates, food, and even sniffing out danger.
So wherever humans are, rats will be there for company too.
Smell you later.
(snake hissing)
- [Narrator] Dear black mamba, we all know your name.
Your reputation precedes you.
Your legend, all fame.
You slither on rocks.
You hop between trees.
You've got a ton of talent, that's easy to see.
But what do they know of you really, dear friend?
Behind the external, the reality. No pretend.
Let's explore a few cool things that you can do.
Dispel all those fears, maybe want some admiration too.
So why do they call you black mamba, anyway?
Your scales are not black, they're more dark gray.
Ah, there it is.
When you open your mouth, black as the night.
Why is it black?
Scientists aren't sure.
Most think, to deter opponents,
the opposite of allure.
But how could that be if you're highly aggressive,
an revenge seeking villain,
striking repeatedly when threatened.
Therein lies the key, you'll fight if you have to.
But if the powers that be challenge you to a quarrel,
a face off as necessary, it's part of the struggle.
That bite of yours is awful, the deadliest of kinds.
Just two drops of that venom
sends razorblades through the mind.
And when you get angry, you can unleash 10 times that dose.
In just 45 minutes, a grown man will be toast.
When the toxins take full effect,
the heart attack comes next.
They should've known better than to mess with such a foe.
You're not down to fight, but you'll wreak havoc for sure.
Hey, black mamba, can we pause your tail for a sec?
There's someone else to introduce.
Y'all may have not have heard of her yet?
The green mamba, so bright and so green.
She's not as well known, but she too can play mean.
A loaner herself, she doesn't look to tangle.
But when she's in need of a meal, hey, we all get angry.
See these monkeys and trees, they're totally unaware.
And when it comes to her prey, she specializes in scare.
Typically dining on birds, eggs and rats.
Right now craving a little white monkey is where she's at.
Her bite is fierce.
The venom spreads fast.
In a matter of minutes, taking a breath might be once last.
A tale of two mambas, their mentality the same.
Their life, just like ours, so much more than a game.
The mythical black mamba, there's no forgetting that name.
But when you think of them, don't get it twisted,
and may its legend forever reign.