Ranking America's Deadliest Snakes (Full Episode) | World's Deadliest Snakes | Nat Geo Animals

0:01 NARRATOR: To most of us, snakes shout danger.

0:06 And that's a valuable instinct.

0:09 Every year, they bite over 5 million people.

0:17 Many have lethal venom; others, primal aggression.

0:23 A handful have both.

0:29 Which snake is the most dangerous?

0:32 It's the one right in front of you.

0:35 What are your chances?

0:37 We'll tally them up and tell you.

0:48 North, Central, and South America.

0:54 Home to over a billion people and millions of snakes.

1:02 From venomous vipers to bone-crushing constrictors,

1:07 which one should you worry about most?

1:17 The Amazon.

1:20 Synonymous with a snake so powerful, it doesn't even need venom to be deadly.

1:30 The green anaconda holds the title; largest and heaviest snake on Earth.

1:40 Nearly 30 feet in length, it's as long as a 10-wheeler truck.

1:50 At a hefty 1,000 pounds, as heavy as a bison.

1:59 Immortalized by film and labeled a vicious man-eater.

2:06 It's a B-grade horror staple— multiple rows of 100 backward-curving teeth.

2:14 But what can it do to you?

2:19 And just how deadly is it?

2:36 On land, most snakes are quick and agile, but not this one.

2:45 Anacondas thrive in a different domain.

2:55 Water.

3:00 It floats their bulk.

3:05 In the water, heavy muscle transforms into supple, athletic movement.

3:17 She can sneak up on you along jungle streams.

3:31 She blends into the mottled riverbed.

3:45 A small nostril and high-set eye is all you'll see of her.

4:01 She can stay under for up to ten minutes at a time.

4:06 You won't see her coming.

4:18 A 1,000-pound snake, right at your feet.

4:24 Her best tactic is the element of surprise,

4:30 and this is what makes her dangerous to humans.

4:42 Around 30 million people share territory

4:45 with anacondas along the Amazon's rivers.

4:49 Ample opportunity for unsuspecting humans to stumble on her.

5:02 But although we may be easy prey, she sticks to a more predictable snake diet.

5:11 Rodents.

5:15 In the supersized Amazon,

5:17 the world's largest snake hunts the world's largest rodent.

5:30 Capybaras hang out in large family groups; safety in numbers.

5:36 (squeaking) With webbed feet and a five-minute breath hold,

5:41 they're also well-adapted to swamp life.

5:51 The anaconda needs stealth and speed to take one down.

6:18 (squealing)♪♪ 100-plus teeth lock on like grappling hooks.

6:37 15,000 muscles crush with the strength of 18 men.

6:49 Tighter and tighter, the extreme pressure overwhelms the capybara's

6:55 circulatory system and stops its heart.

7:04 Then, she pivots her jaw and stretches it.

7:10 Super-elastic ligaments allow her to swallow massive prey.

7:20 This capybara is the weight of a full-grown man.

7:30 It's not surprising the green anaconda is the most feared snake in the Amazon.

7:39 So, how does she score?

7:42 Aggression in truckloads.

7:45 No venom, but a vicious bite and deadly muscle power.

7:51 Your chances of walking away are high, but still,

7:55 a handful of people fall prey to the mighty anaconda each year.

8:00 She takes her place at the top out of the gate.

8:08 The anaconda lurks beneath, but the red-tailed boa watches from above you.

8:24 She's a twentieth of the weight of her Amazonian cousin,

8:28 but that's still a 50-pound snake.

8:47 These bruisers can't bend and slither.

8:51 Instead, they use their flexible belly skin

8:53 to scoot forward without bending their spine, like giant caterpillars.

9:13 She's as thick as your thigh, and she's getting too big for her skin.

9:19 (birds squawking) During a growth spurt,

9:24 snakes secrete a lubricant between their top

9:27 layer of scales and the layer beneath.

9:34 Which allows them to slip off their old

9:39 skin and emerge shiny, supple and bigger.

10:00 When they're young and small, many boas are sold as pets.

10:06 But the snakeling will grow at least 10

10:09 times in size by the time it reaches adulthood.

10:17 A 10-foot predator in your child's bedroom is definitely not a good fit.

10:32 More than 20 cases of children being strangled or killed

10:35 by their pet boas are on record in the USA alone.

10:42 It's innocent, but the red-tailed boa

10:45 remains one of the world's deadliest snakes.

10:51 Considering this childhood pet can live as long as 40 years in captivity,

10:56 boas are best left in the wild, hunting for their own natural prey.

11:11 NARRATOR: In the deeper shadows of the Amazon Basin, danger awaits.

11:16 (howling) This big hitter brings venom to the table.

11:29 The South American bushmaster.

11:36 He's the longest venomous snake in the entire Amazon.

11:41 Averaging over 6 feet in length and sometimes reaching nearly double that.

11:52 He's also a top contender for the longest fangs of any snake.

11:59 Add potent venom, and he's up there with the deadliest snakes on the continent.

12:10 But what are your chances if you're faced with one?

12:18 Unlike the constrictors, he uses venom to immobilize his prey,

12:25 backed by a highly sensory strategy to track down his dinner.

12:39 He uses his tongue to follow scent trails.

12:54 A snake's tongue is 10,000 times more sensitive than the human nose.

13:02 He's collecting scent particles from the air.

13:10 Then he "tastes." A special organ on the roof

13:13 of his mouth processes the scents into information.

13:20 He can even taste in 3D;

13:23 picking up different scents from left and right, on each fork of his tongue.

13:37 Rodents reuse paths fairly regularly,

13:41 so the resourceful bushmaster just needs to follow

13:44 the "rodent runway."♪♪ If he waits long enough, his dinner may come to him.

13:57 (birds chirping)♪♪ If you tread on him now, you're in trouble.

14:10 They're called pit vipers because of those holes below the eyes.

14:15 Each contains heat-sensitive organs that detect minute temperature changes.

14:23 The rat approaches.

14:27 The bushmaster's already mapping its body heat.

14:54 (hiss) (squeaking) 1 1/2-inch fangs, like hypodermic needles,

15:04 deliver a massive dose of venom,

15:06 which destroys tissue and causes internal bleeding.

15:11 Fangs so long, venom goes deep into muscle.

15:23 You'd stand a 20% chance of surviving this bite.

15:28 The rat?

15:30 Zero.

15:40 Using only the fangs, he guides his meal down his gullet.

15:52 Despite his size, the bushmaster gets by on 10 large meals a year.

15:59 This rat could last him a month.

16:09 The bushmaster brings venom and supersized weaponry right to our feet,

16:15 but his habitat is remote, dense forest.

16:20 So, he doesn't come into contact with people often.

16:26 When he does, he tries to warn you.

16:31 He shakes his tail in defense, But there's no tell-tale rattle.

16:36 (slapping) It's earned him his Latin name:

16:45 "silent fate."♪♪ Bushmaster venom is unforgiving,

16:52 and the antidote is unreliable.

16:56 He keeps his aggression in check by steering clear of humans.

17:01 But when he does bite, people lose limbs and lives.

17:10 The bushmaster's venom puts him in pole position.

17:19 In the open undergrowth of Costa Rica, a killer with manners.

17:31 NARRATOR: Rattlesnakes are more upfront than bushmasters.

17:35 They use their noisy tails to warn, "Back off.

17:39 I can kill you." (rattling) (rattling) Locals call this one cascabel,

17:56 after a dried chili pepper with rattling seeds and a searing burn.

18:05 When rattlers shed their skin,

18:07 a small section stays behind on the base of their tail

18:10 and hardens into a new segment of the rattle.

18:15 One segment knocks against another,

18:18 and that's what you hear when you walk too close.

18:21 (rattling) Rattlers have a habit of sitting tight, not fleeing.

18:37 And when they strike, they're lightning fast.

18:42 From 0 to 100 miles an hour in just a tenth of a second.

18:47 That's 50 times faster than a Formula 1 car out of the starting blocks.

18:58 (man groans) Their venom is monstrously toxic.

19:04 It attacks both the circulatory and the nervous systems.

19:08 (rattling) A two-pronged approach.

19:14 First, searing pain as hemotoxins swell, bruise and blister the bite site.

19:20 (rattling) Then, wrenching muscle spasms and respiratory

19:27 distress as neurotoxins damage and paralyze nerves.

19:35 Finally, a strong chance of death from respiratory failure.

19:43 (rattling) Cascabel venom can rupture your organs and stop your heart.

19:53 They're aggressive and quick to strike.

19:55 Responsible for thousands of human snakebites per year and a high fatality rate.

20:02 It's more than enough to outgun the non-venomous

20:06 constrictors and bump the bushmaster into second place.

20:14 Central America— a diverse snake habitat, also highly populated by humans.

20:24 A recipe for disaster?

20:27 Most definitely.

20:30 There's a niche for each of the hundreds of snake species;

20:34 every one of them specialized killers.

20:39 Central America is an evolutionary snake pit.

20:49 Snakes across the globe live right under our noses.

20:56 And many are much closer than you think.

20:59 (vendor shouting) Some take camo to new heights,

21:05 making them almost invisible to the human eye.

21:11 The eyelash viper is so cryptic that she often winds up in our midst,

21:15 right across Central America.

21:20 Ending up at this busy market wasn't the plan,

21:25 but she's trying her best to blend in.

21:33 Because of her weaponry, she's a deadly neighbor.

21:48 A bite from this beauty is serious.

21:54 It's not her fault, but her venom is potent and sometimes fatal.

22:02 Why so dangerous?

22:07 It's a side-effect of being a perfectly evolved forest hunter.

22:19 Lash-like modified scales protect her eyes

22:23 from prickles and thorns in dense rainforest.

22:27 A neat accessory when you don't have eyelids.

22:34 A further attribute is her incredible prehensile tail,

22:38 which holds her just at face height.

22:44 Like a deadly bungee cord.

22:52 Waiting, not for you, but her prey.

23:04 NARRATOR: Inside her mouth,

23:06 a specialized tube allows the eyelash viper to breathe

23:09 if her throat is crammed with large prey,

23:12 and an impressive set of fangs fold back parallel to her jaw,

23:16 ready to be unleashed.

23:19 (frogs chirping) All this deployed at human head height.

23:29 (hiss)♪♪♪♪ Like the cascabel,

23:44 the eyelash viper has both hemotoxic and neurotoxic venom,

23:49 inflicting massive hemorrhaging and a swift death on her victims.

23:55 She's not aggressive but comes into contact with people often,

24:01 pushing her defensive bites into the double figures.

24:05 At worst, causing one fatality per year.

24:10 Still good enough for a worthy third place on the leaderboard.

24:19 Over 300 million people.

24:23 Over 20 species of venomous snakes.

24:28 North America is snakebite central.

24:32 Between 7,000 and 8,000 people are bitten every year.

24:39 You're in big trouble if that bite is from one of these two.

24:45 Hugely different in looks and M.O., but both armed with deadly venom.

24:53 The coral snake has the opposite of camouflage.

24:57 It uses color as a siren.

25:01 "Stay away.

25:02 Don't touch."♪♪ Most snakes sit tight or flee,

25:10 but corals are movers and shakers.

25:15 Their tiny fangs leave a mere pinprick

25:18 and only deliver 1/1000th of a teaspoon of powerful,

25:23 neurotoxic venom, but that's all that's required

25:27 to kill us and their prey— other snakes.

25:37 (hiss)♪♪♪♪ Their bright, shiny scales just beg to be touched,

25:52 but that's not their game.

25:54 (children talking)♪♪ (children talking)♪♪ They're shy

26:08 and often use deception as defense.

26:13 Being conspicuous, they resort to hiding their bodies.

26:17 Leaving a loop of tail aboveground as a decoy

26:21 to draw attention away from their heads.

26:23 (children laughing)♪♪♪♪ If a predator reaches

26:35 for the bright loop, the coral strikes.

26:42 GIRL: Ow!

26:46 BOY: Maggie!

26:48 NARRATOR: It's no more than a pinprick,

26:50 and symptoms can take a whole day to appear.

26:59 By then, it's too late.

27:02 Neurotoxins disable the nervous system,

27:05 disrupting the connections between the brain and muscles...

27:09 (crash) (siren) ...leading to respiratory or cardiac arrest.

27:20 In North America, this toy-like snake is responsible

27:25 for up to two dozen bites per year, most of which are extremely serious.

27:32 They are so feared that some snakes take advantage of their reputation.

27:39 Mimicking his stripes, the harmless false coral snake fools predators

27:44 into thinking he's his highly dangerous cousin.

27:50 True coral snakes are the tricksters in the pack.

27:54 They're small but potent.

27:56 Deadly but shy.

28:00 Which keeps them in line behind

28:02 the vicious vipers and the colossal constrictors.

28:11 America's cliché— cowboy country.

28:16 (horse neighs) (bird shrieks) And home

28:22 to the most notorious vipers on Earth: rattlesnakes.

28:28 (rattling)♪♪♪♪ (rattling) The western diamondback.

28:46 Icon of the Wild West.

28:52 His signature rattle strikes fear into both man and beast.

28:56 (rattling) Ironically, he can't hear it himself.

29:02 (rattling) Snakes have no eardrums.

29:10 Instead, his bulky bottom jaw acts as an antenna,

29:14 tuning in to the smallest vibrations in and on the ground.

29:21 (cattle lowing) He feels the cowboys passing.

29:27 (hoofbeats) (horse neighs) His instinct is to stand his ground.

29:34 (rattling) (horse neighs) (rattling) He'd

29:40 rather avoid confrontation than strike unnecessarily.

29:44 (rattling) (moo) He's known to kill livestock, but that's not his intention.

30:03 Ranches are ideal breeding grounds for his favorite prey: rodents.

30:17 NARRATOR: Is the western diamondback a pest or pest controller?

30:21 (wings flapping)♪♪♪♪ Opinions may differ, but like all snakes,

30:38 the rattler needs to kill to survive, and there's a juicy meal in this barn.

30:56 His tongue is his GPS, tracking scent cues in his surroundings.

31:14 Like the bushmaster,

31:16 he's not actively stalking but smelling his way to the best ambush site.

31:34 In the gloom, his thermal pits paint a picture in body heat.

31:44 So, he can "see" the rat, even in pitch darkness.

31:59 Now, he just needs patience.

32:23 (squeak)♪♪ (squeak) Tag and release.

32:32 One strike is all he needs.

32:36 The rattler's huge venom glands hold enough hemotoxins to kill 300 mice.

32:44 But he controls how much he delivers.

32:53 It's not long before his prey succumbs to the potent, fast-acting venom.

33:00 Without limbs or teeth to tear food into bite-size chunks,

33:05 snakes swallow their prey whole.

33:12 Venom is incredibly helpful.

33:16 It starts to digest the meal, even before the snake has swallowed it.

33:24 Their toxic drool has become their finest defense.

33:31 So effective, that both man and beast yield to snakes.

33:41 In cowboy country, that's important.

33:50 Where western diamondbacks and human territories overlap,

33:53 thousands of people are bitten each year.

33:58 So, how do they tally up against their rivals?

34:03 Huge venom yield.

34:05 Defensive attitude.

34:07 Frequent bites, with a high mortality rate.

34:11 They outgun the previous contenders on every count.

34:16 It's a sharp shoot to the top of the leaderboard.

34:25 When judging a snake's deadliness, size, fangs and venom are big factors.

34:35 The eastern diamondback rattlesnake has all three.

34:45 He's the largest and heaviest rattler,

34:51 armed with the longest fangs and deadly venom.

34:57 When a fang starts to wear out, another replaces it.

35:05 Long fangs deliver venom deep into the internal organs,

35:11 quickly destroying tissue and rupturing blood vessels.

35:16 If this snake bites you, you'll be lucky just to lose a limb.

35:26 It's good news that the eastern diamondback sticks to dense,

35:30 remote habitat, well away from humans.

35:37 He's master of the undergrowth.

35:45 Instead of us, he shares habitat with another deadly snake: the cottonmouth,

35:54 or water moccasin, the only semi-aquatic pit viper in the world.

36:02 He makes his living on a diet of fish,

36:07 frogs and other amphibians, but he's also an opportunist.

36:14 And this is a snake-eat-snake jungle.

36:23 Cottonmouths are cannibals.

36:30 Head-to-head, the snake that strikes first, lives.

36:35 This cottonmouth is much bigger.

36:47 He has the eastern diamondback for breakfast.

36:52 (rattling) The rattler's immune to the venom

36:59 of his own species, but not to others.

37:06 Antibodies in the cottonmouth's blood protect him from his toxic prey,

37:11 breaking down the deadly diamondback venom as he ingests it.

37:26 To fellow snakes, the cottonmouth is a deadly rival,

37:30 but he lacks the potency and aggression of the rattlers.

37:35 He bites a few hundred people per year,

37:38 but with the right antivenom, survival rates are good.

37:45 The eastern diamondback has more potent venom,

37:48 which translates to a 30% mortality rate if you're bitten.

37:54 He ups the stakes to top his competitor

37:57 and become the deadliest snake on the chart...for now.

38:07 We've seen snakes that rattle and snakes that roll,

38:14 some that deceive and others that cannibalize.

38:23 But who's the deadliest of them all?

38:31 NARRATOR: Like humans,

38:32 snakes have colonized most of the habitable parts of our planet,

38:39 but where our lives intersect, it often ends badly.

38:45 (rattling) Put a venomous, stealthy, defensive super predator amidst humanity...

38:53 the stakes don't get higher.

38:57 In the Americas, one snake comes into contact with humans more than any other.

39:05 (birds chirping) The fer de lance.

39:11 (chirping) He's got the full package: camouflage, massive fangs,

39:21 lethal venom, thermal pits and a notoriously vicious disposition.

39:31 Strike first, ask questions later.

39:34 (hissing) (hissing) He's not afraid of anyone.

39:43 (hissing) In Central and South America,

39:51 this feisty little snake bites tens of thousands of people every year,

39:59 and hundreds of those strikes are fatal.

40:06 Why?

40:11 His lance-shaped head is a dead giveaway, but he's fast and hard to see.

40:27 His camouflage is so effective that you don't see him before it's too late.

40:43 He's not an intentional villain;

40:47 the fer de lance is also drawn to settlements where rodents are rife.

40:52 (hiss)♪♪ (birds chirping) Both hemo- and cytotoxic venom

41:03 kills quickly and destroys blood cells and tissue,

41:07 ravaging internal organs and causing the victim to hemorrhage fast.

41:16 With people at large and sunny porches

41:19 to bask on, that's a disaster waiting to happen.

41:31 (macaw squawking) This young lancehead has enough venom to kill four men.

41:39 (squawking)♪♪ Far from medical facilities and antivenom,

41:47 an amigo caught napping could be dead in a matter of hours.

41:51 (squawking)♪♪♪♪ (hissing) (squawking) Wrong place, wrong time.

42:28 The fer de lance is not the biggest or the strongest or even the most venomous,

42:36 but tally up its notoriously aggressive attitude, its proximity to humans,

42:41 and its high strike rate, the results are clear.

42:46 The fer de lance kills more people in South America than any other snake.

42:54 It's enough to pip the rattlers to the post

42:57 and top the chart as the Deadliest Snake of the Americas.

43:14 Ever since Eve took the apple, snakes have had a bad rap...

43:19 (hiss) ...but in reality, they don't actively set out to harm humans.

43:26 (siren) A life without limbs has armed them

43:31 with an arsenal of skills to master their environments:

43:36 chemical weaponry, highly evolved senses and incredible muscle power.

43:45 Without snakes, rodents would run riot,

43:48 agriculture would be plagued, homes would be infested.

43:55 (squeak) We may fear them, but give them space.

44:02 Snakes make the world a far less dangerous place.