You may not want to encounter one in the wild.

To each their own!

That's why we're here, to take you on a world tour

of some of nature's most incredible snakes from the safety of your home—

and with your very own intrepid guide.

All the snakes we'll be visiting belong to a group called the vipers.

As of 2021, there are 368 species of viper worldwide.

The name comes from the term viviparity, which means giving birth to live young.

Unlike most snakes, which lay eggs,

most vipers have eggs that hatch inside the mother,

who then gives birth to up to dozens of tiny snakes.

Not glad you're safe at home yet?

Vipers are also often highly venomous,

with two hollow fangs that fold flat to the roofs of their mouths.

This allows the fangs to be extra long,

unfolding into imposing weapons when the viper prepares to strike.

So how about we pay them a surprise visit?

First stop: the southeastern United States,

where we can hear the viper before we can see it.

The eastern diamondback rattlesnake is the largest of 36 species of rattlesnake.

Rattlesnakes can shake their rattles up to 90 times per second

to warn off predators for hours if needed.

The rattle consists of hollow, interlocked segments made of keratin,

the same substance that makes our nails and hair.

When the snake shakes its tail, these segments hit each other,

creating a shockingly loud noise.

Now onto the mountains of western Iran, where a spider crawls across a rock,

making easy prey for a passing bird— or not.

The spider-tailed horned viper is perfectly camouflaged, almost invisible,

except for its unique bulbous tail-tip with long drooping scales

that look like a leggy spider.

Spider-tailed vipers are only about 50 centimeters long,

so they can lure small birds within striking range

without compromising their ability to squeeze into narrow rock crevices.

In the rainforests of Latin America lives a viper

that couldn't be more different from the spider-tailed viper—

if you can find it.

It's one of the most elusive snakes in the world:

the bushmaster.

The bushmaster is a pit viper.

Between each eye and nostril, it has a heat-sensing pit

with a membrane covered in highly sensitive receptors

that respond to temperature changes

as small as one one-thousandth of a degree Celsius.

These pits gather infrared information that is integrated with visual information

in the optic tectum.

This allows the bushmaster to “see” the heat signature

of approaching prey or predators,

helping it decide whether or not to strike and strike more accurately.

This comes in handy for guarding a nest—

unlike most other vipers, the bushmaster lays eggs

in hollowed out tree buttresses or burrows made by other animals.

It must be large enough to defend its nest—

in fact, the bushmaster is the largest viper in the world,

reaching lengths of over 11 feet, with huge fangs and deadly venom.

Meanwhile, in the forests of sub-Saharan Africa,

there's a shorter, chunkier viper that's even more venomous than the bushmaster.

The African Gaboon viper has the longest fangs of any snake—

yes, all 3,879 snake species, not just vipers—

and can deliver 1,000 milligrams of venom in a single bite—

enough to kill ten adult humans.

Although deadly, Gaboon vipers have a reputation

for being slow-moving and placid creatures.

When they do strike, they hold onto their rodent prey while the venom takes effect,

then quickly swallow it down.

At this point, you may be worrying about our guide— but never fear,

rodents like our little desert kangaroo rat have their own skills

to evade the serpent's tooth.

They stomp their feet at rattlesnakes, kick sand towards them,

and evade their strikes with acrobatic leaps and powerful kicks—

helping them live to guide another snake tour.