THIS COBRA HERE WAS FOUND IN THE RUBBLE HERE OF MY GARDEN.
AND THAT'S VERY COMMON.
YOU OFTEN FIND COBRAS IN SITUATIONS LIKE THIS.
AND IT'S AN AMAZING SNAKE.
MOST PEOPLE THINK IT'S ONE OF THE MOST AGGRESSIVE SNAKES.
THEY THINK THAT THIS IS A SNAKE THAT WOULD INTENTIONALLY ATTACK YOU, THAT'LL GO FOR YOU.
THAT'S NOT AGGRESSION.
THAT SNAKE IS MERELY TRYING TO WARN ME OFF.
IT'S STANDING UP SO THAT I CAN SEE IT, AND I'M SUPPOSED TO NOW MOVE AWAY FROM IT.
IF I MOVE AROUND IT HERE, YOU'LL SEE HOW IT FOLLOWS ME.
IT'S, OF COURSE, GOING TO FOLLOW EVERY STEP THAT I MAKE.
SNAKES RESPOND TO MOVEMENT, THE COBRA ESPECIALLY.
I'M GOING TO SHOW YOU SOMETHING REALLY INTERESTING HERE.
THIS COBRA IS REALLY WARNING ME WITH ITS HOOD.
AND IF I GRAB IT REALLY GENTLY, AND RESTRAIN IT, HOLD IT LIKE THIS FOR A MOMENT, ONCE THIS SNAKE FEELS THAT IT'S COMPLETELY OVERPOWERED, ONCE IT FEELS THAT IT CANNOT DO ANYTHING ELSE, THAT IT CANNOT MOVE AWAY FROM ME, CANNOT SPREAD ITS HOOD, BITING IS NOT WORKING, IT MAY DO SOMETHING WHICH IS GOING TO REALLY INTEREST YOU.
IT MAY PRETEND TO BE DEAD.
AND EVEN IF I MOVE MY HAND OVER IT, IT'S RESPONDING COMPLETELY DIFFERENTLY TO THE WAY IT WAS A MOMENT AGO.
ISN'T THAT INCREDIBLE?
SNAKES ARE SO FASCINATING.
THIS PROGRAM WAS MADE POSSIBLE BY CONTRIBUTIONS TO YOUR PBS STATION FROM VIEWERS LIKE YOU.
McGILLIN: Snakes are reptiles most of us prefer not to meet.
( tail rattling ) And they're wary of us, too, which is why they hiss or rattle to warn us off.
( tail rattling ) Such warnings are ignored at our peril.
( tail rattling ) But a snake will only bite in defense and only if it feels gravely threatened.
It's easy to imagine the snake as an aggressor-- the snake in the grass, a deadly foe.
But why does this image send a shiver of fear down our spines?
In shape and movement, they are so different from us that legend and folklore have given them a sinister reputation they don't really deserve.
How can we understand an animal that smells with its tongue or that hears with its whole body, sensing vibrations?
The hypnotic stare of its unblinking eye can seem as alien as its apparent rebirth through the shedding of its skin, sloughed off like a scaly ghost of itself.
Among them are giants that storybooks say are a hundred feet long and ready to strangle unwary jungle explorers.
( bird squawking ) And yet there is this little guy-- a thread snake, very friendly and not deadly at all.
There is even beauty and grace in some as they go upon their bellies, silently through the trees.
But where did snakes come from?
An animal that looked much like some other reptiles alive today.
It's hard to believe that snakes have anything in common with creatures like this.
But in fact, every reptile descended from the same ancestor.
This primitive ancestor led to two groups of animals-- turtles and all other reptiles.
All through the age of the dinosaurs and during the emergence of lizards, snakes were nowhere to be seen.
But there were legless lizards, and it was from these that snakes evolved.
For 110 million years, they have been living side by side with other reptiles.
Today there are more than 2,500 different species of snake.
Hidden within their bodies, vestiges remain of the legs they lost.
But snakes, with a skull, backbone and a multitude of ribs, are able to move quickly in several ways.
The serpentine crawl of the cobra-- most snakes move like this.
The movement creates little ridges in the ground, which the snake pushes against to propel itself forward.
When you're short and fat, like this puff adder, throwing cobra-style loops is impossible.
Instead the muscles act on the ribs.
As the ribs move, the snake's scales grab hold of the ground and with a series of rhythmical contractions, the snake rows along in the sand.
The famous sidewinder favors the serpentine wave and like the cobra, it can push itself against the ridges it nudges up in the sand.
By moving sideways, it needs only two points of contact on the very hot sand.
At any one time, most of its body is held in the air.
Who needs them?
There are different problems for a tree-climbing python in a rain forest.
To reach across a gap, it can stiffen sections of its body, becoming its own ladder from branch to branch.
This sinuous and flattened body, with its broad tail working like an oar, could be mistaken for an eel.
But this is no fish.
It's a sea snake.
Most snakes can swim, though even the sea snake must interrupt its hunting now and then for a breath of air at the surface.
As hunters in water or on land, snakes are silent and efficient killers.
A rattlesnake has more than its bite to work with.
Its tongue constantly tastes the air, scenting for prey.
Its body senses ground vibrations, even the footsteps of a mouse.
Standing still is no defense.
The rattler is also able to sense body heat.
Infrared heat, detected by sensory pits on each side of the face, pinpoints the prey.
( gun cocks, then fires ) Their high-tech weaponry has been around long before ours.
But in any combat situation, defense is as important as attack.
( helicopter roars overhead ) This military training ground is home to two other opponents.
The rare red-cockaded woodpecker lives in this loblolly pine.
( bird chirps ) Its enemy is a corn snake, whose tactics are to climb the tree and steal the woodpecker's chicks.
The bird's defense is to peck at the tree, releasing its resin.
( chirps ) But how can resin repel this relentless invader?
( chirps ) It's getting close.
Will the woodpecker's weapon really work?
The resin goes into action.
Seeping between the scales, it irritates the snake's skin.
Woodpeckers, one; corn snakes, nothing.
Australia-- home to the most venomous snakes in the world.
In these cane fields lives one of the most deadly.
But why do snakes need venom?
This inland taipan is hunting rats.
The cane fields are alive with them.
But they are dangerous prey.
Rats can bite back.
( rat squeaks ) A snake's head contains all its sensory equipment-- eyes, taste, smell, brain-- and the head is vulnerable.
It bites and retreats immediately.
The head is undamaged and the venom is doing its work.
The rat is now paralyzed.
The snake can safely approach its prey.
Venom gives the snake two huge advantages.
It not only kills the prey, but by the time the snake begins to swallow the rat, the venom has already begun to digest it, breaking down cells in the body.
The venom in a baby snake can be even more powerful than the adult's.
This young cantil viper is luring prey with its wormlike tail.
The frog is deceived by the enticing movements.
( snake hisses ) Unaware of its lucky escape, the frog remains convinced there is a worm there.
Amazingly, the frog seems unable to see the snake.
The venom acts quickly, subduing the frog.
The young viper catches mainly amphibians, but as it grows older, the chemistry of its venom will change to suit other prey.
Donald Strydom works with South African snakes to understand how venoms affect the bodies of prey animals and how the venom is delivered during a bite.
STRYDOM: The snake that I've chosen here is a puff adder, and they've got the very long front hinged fangs with a cytotoxin, a cell-destroying venom.
I'm going to very carefully open up the snake's mouth and show you this mechanism.
The snake doesn't like its mouth to be opened; it's much like you going to the dentist and having your mouth prodded into.
Now, the fangs lie against the palate of the mouth, so if I just open there, you can hardly see the fangs.
But if I now slip my stick just behind the fangs and get them forwards, you can very clearly see how they hinge.
Now, the fangs are covered by skin sheath here.
I'm going to try and slip this sheath up so that one can see the naked fang, and there we have one fang nicely exposed.
These fangs are hollow.
They work like little hypodermic needles.
So they inject venom through the fang into its victim, and, in fact, you can see a tiny droplet of venom on the one fang there.
You know, the venom glands of a snake are very similar to the saliva glands in a human, in that if we have a dry mouth, our body very easily reproduces saliva.
And the mechanism with a snake is almost exactly the same, in that venom is never easily exhausted.
Under normal conditions, the snake is never without its venom.
McGILLIN: A Gaboon viper produces venom in huge amounts.
It's a large fat-bodied snake and needs to have a lot of venom to subdue large prey quickly.
The viper is too slow to chase its victim.
To inject such large quantities, the Gaboon viper has the longest fangs in the world.
Each is almost as long as a human thumb.
That's quite a bite.
Even a smaller bite is no fun.
Venom is breaking down the cells inside this man's punctured leg.
He's not feeling too bad now, but measurements show his leg is swelling fast, a sign that the snake injected a potentially fatal hit of venom.
Blood vessels are rupturing; fluid is accumulating as tissues break down.
Only the correct antivenom can stop the process before vital organs are damaged.
Antivenom is a specially prepared fluid, a serum containing antibodies, proteins that will neutralize the venom in the snakebite.
The patient has survived the night, but the tissue damage continues for a while-- there is still venom present.
Although snakes are not trying to kill us, it's worth knowing how some of them bite.
STRYDOM: The next snake that I have here, it's Africa's most venomous snake.
And this is a boomslang.
It has, drop for drop, the strongest venom of any snake in Africa, more so than a black mamba or any of the cobras.
Most people think that a back-fanged snake can't bite onto a large part of your body.
Most people think the boomslang can only latch onto your earlobe or small finger, whereas you can see here this is not true, in that the whole head of the snake is divided in half by its mouth, and they can open up that mouth to about 120 degrees.
And with the mouth that wide open, they could very easily bite you on the flat of your hand or the top of your leg, wherever it pleases.
If you were bitten by the snake, you would literally bleed to death.
So what's going to happen to you is that you're going to bleed into your heart, into your stomach, into your bowels.
You're going to be urinating blood, defecating blood.
And it's a... really a horrific way to die.
McGILLIN: This poor frog is about to be the victim of a vine snake in Central America.
This snake is also back-fanged, just like the boomslang.
Fortunately, for small prey, death comes quickly.
The venom of some snakes with fixed fangs attacks the nerves.
STRYDOM: Well now, the front fixed-fang snake that I've chosen is a snouted cobra here.
These fangs are much smaller than the front hinged fangs of an adder.
Those fangs don't have to fold backwards.
You see, they remain erect in the mouth.
So the snake merely has to snarl its mouth and so inject his venom.
And sometimes a mere scratch is enough to kill you.
The neurotoxins would interfere with the neurocommunication system of our body and paralyze the vital organs-- so the heart or diaphragm muscle-- and one would die from asphyxiation.
You literally cannot breathe and possibly die of heart attack.
McGILLIN: In most countries where people face a daily risk of encountering snakes, woodpiles and exposed trash heaps are surprisingly common.
Yet all can encourage snake trouble.
Woodpiles provide shelter for snakes, and trash attracts rats.
What better prey is there here in Africa for a black mamba?
Six feet of powerful hunter, it haunts the outbuildings and can strike like lightning with a quick-working venom.
To a black mamba, this bungalow is just another place where food may be in good supply.
Inside, Tony Morgan confronted an uninvited guest, and it bit him.
MORGAN: This is a typical corner that snakes like to hide in, and it was a similar corner like this near my front door on the farm that I found a mamba all curled up here with my fishing rods and various things like that.
And as I don't kill anything, particularly snakes, I grabbed this particular implement, and I thought that...
I hooked him out, and I thought I had pinned him down.
Unfortunately, he was able to stretch quite a bit and he got me just below the knee with one fang.
I then lasted exactly 30 minutes.
Ann, my wife, got me down to Donald's place very quick.
And then he took over and drove me down to the hospital, where we were fortunate in finding a doctor on duty, and 30 minutes after the bite I said to him, "I cannot exhale anymore."
And he said at the same time, which I didn't hear, um, "His heart has stopped as well."
So, in effect, I was dead at that time.
( hisses ) McGILLIN: Bill Haast in Florida is the kind of person to whom Tony Morgan owes his life.
But collecting venom to make antivenom has almost cost Bill his own life.
HAAST: I was bitten by a cobra and ended up in a respirator.
I had stopped breathing.
I was bitten by a mamba in the leg, a king cobra bite in the knee.
Well, my blood pressure went to zero.
But the most recent one was a canebrake rattlesnake, couple of months ago; I got bitten in the back of the hand.
That was almost pure carelessness.
McGILLIN: Bill, who's nearly 90, milks venom into a collecting jar while he gently squeezes the venom glands.
But how has he survived 168 bites?
The answer may be quite natural.
The South African Cape cobra, a highly venomous snake, is prey to meerkats.
But why are meerkats apparently unaffected by frequent cobra bites?
They seem to be immune.
Perhaps the frequency of such bites is a clue to Bill's survival.
HAAST: Back in 1948, September the 18th to be exact, I started to immunize myself with venom from the Cape cobra of South Africa.
I diluted the venom 10,000 times and took one-hundredth of a milliliter.
Then I graduated, or increased, the dose over months and then eventually years, added different species until now, usually once a week, I take a booster, and it's a mixture of 32 different species.
So I know that got me through a lot of these bites, at least over the threshold if not, in most cases, saved my life.
McGILLIN: Snakes and humans share the world uneasily.
This spectacled cobra is common in the paddy fields of India.
Every year, more than 10,000 people are killed here by snakebite.
Antivenom is unavailable.
For the same reason, snakebite is a major killer across Central and South America, Africa and Southeast Asia.
It's hard to arrive at an exact number, but at the lowest estimate, 50,000 people die each year.
( hisses ) In South Africa, Donald Strydom is answering an emergency call.
In this part of South Africa, we have a lot of venomous snakes.
People are active in the field here; they often come across snakes.
They find them in their houses, and that's when we are called out.
Seems to be the place over here.
Lots of people standing around there.
McGILLIN: A snake in a house is a cause for local excitement.
But the occupants have already followed the right emergency procedures.
Everyone has left the house, and they've not only closed the door but sealed it as well with a towel.
Donald can be fairly sure that the snake is still inside.
What I'm going to do here is, um, actually put a visor on because in a situation like this, it's very possibly a spitting snake.
So I'm just going to get a few things that I need here.
Yeah, there is really a lot of hiding places here.
A snake could be anywhere.
Um, this is really, yeah, a bit dark in here as well, so one's got to be really careful.
Just take care where you walk over there, um... Just take it easy.
There are places around here where it could easily just spring out on you.
If you guys just stay back a bit there, I'm going to have look in these dark areas.
Now, you just stay in the open area of the floor, because I suspect it to be behind things around like this here.
Oh, that's clear, um... You know, we could so easily find a mamba in a place like this.
And these things are like coiled springs.
I mean, once it feels that it's not hidden anymore, it could just come flying out.
You see, these are perfect.
You find rodents here as well, and this is what the snake was probably looking for, or to just try to hide from the disturbances outside possibly.
Now, this whole area is really, really good.
Look at these mats under here.
No, nothing there.
Um... you know, they can...
I don't know, sometimes they even find an escape.
They could actually maybe even get out from where...
The door's plugged out there; it could have pushed past there.
But, um, I think we just maybe should carry on looking.
You know, it could have also climbed.
I mean, these walls are pretty rough up here, but I could take a look somewhere up here.
Whoops, there is something up there.
There's something in the corner over there.
Um... Yeah-- okay, without a doubt that's a mamba.
It's a black mamba.
There's a piece of coil just around the... between the roof and the wall there.
We know that mambas are very, very poisonous.
I mean, if this bites us, we're quite far from a hospital now, so we've got to be really, really careful.
And if you can just stay in the furthest corner away from me there, just out of my way, I'm going to bring it down and just get it straight past you outside, and then deal with it, get in into the bag.
Okay, it's trying to edge away from me there.
Its head's out again.
Yep, it's opening up its black mouth at me.
It's warning me.
You know, it's interesting that the snake doesn't just come out attacking.
But at this stage, having it like this, it obviously feels threatened.
At this stage, it'll bite whatever comes near to its mouth.
And that... ooh, it's a big snake.
It's bigger than I thought.
It's a long animal.
Just watch it behind me there.
Please don't come any closer than that.
Now, the snake's obviously hyped up now, and whatever touches it through the bag, it's going to bite.
And it can see through the bag here.
I'm just going to pin it down to the side, make sure that it's safe in one area, and then I'm going to release the head.
Just take care there.
Don't come too close now.
You just touch this bag and this thing bites.
I'm going to find a safe place to release it.
Let's get it in there.
And I think I should go and reassure the lady here that her house is clear of snakes, and that it's safe to go back in again.
McGILLIN: Housewives in India are troubled by snakes as well.
The men of Vindrawan have also made a profession out of removing them.
( man speaking local language, dogs barking ) McGILLIN: He's not going to let this cobra go free.
For hundreds of years, this has been a village of snake charmers.
( pipe playing high-pitched tune ) The snake is captivated by the swaying pipe, following every rocking movement.
And that's the snake charmer's secret.
The music plays no part.
It's probably too high a frequency for the snake to appreciate.
It has no eardrums.
Sound vibrations are perceived only by way of the skin, muscle and bone.
( snake hisses ) Bites are a routine hazard for charmers.
But they have a special snake stone, which they believe can magically draw venom from the wound.
Survival is most likely to depend on the snake only biting in defense, using little or no venom.
Also, the victim himself may have received many mild bites in his lifetime and developed some immunity.
But the piece of soapstone is the treatment they believe in.
This baby cobra in Africa is one snake that no snake charmer would ever use.
It threatens the civet cat by standing tall and looking big.
But it has another weapon.
( grunts ) This is a spitting cobra, and it sprays venom, which irritates the eyes of the attacker.
It's not lethal, but it works.
( animal grunts ) McGILLIN: South America-- the llanos of Venezuela, the wetland home of the largest snake in the world, the anaconda.
This giant has no venom at all.
To capture prey, it relies on muscle power, coiling around its victim and squeezing the breath out of it.
And a large snake needs large prey.
The biggest rodent in the world fits the role.
A capybara, the size of a pig, is fairly easy to ambush as it bathes in the warm waters.
The snake must have teeth strong enough to hold on to such lively prey and be ready to loop its body tightly around the capybara to avoid being bitten or scratched.
The anaconda, the most powerful of constrictors, moves in.
( movie soundtrack music plays ) FILM ANNOUNCER: Look out, Jimmy!
I can't hold it.
Mike hears his cries for help.
Jim is black in the face, almost done for.
McGILLIN: To be safe, the actor needed to know exactly how a large constrictor kills, just as Donald Strydom does.
STRYDOM: I caught this snake on somebody's farm.
It had eaten something really large, and the farmer was worried it's going to eat his dogs or even maybe his children, which isn't totally unrealistic.
Have a look at that.
It's getting me around the arm here.
I can really feel it in this area here.
I mean, you can see how it's stopping the blood supply there.
And this is my arm, so I can handle it.
I can wrap it off me here.
But can you imagine that around somebody's neck?
I mean, that's pretty tight over here.
This movie that we watched-- we've just seen it with this Jimmy, where it had wrapped around him.
It wasn't totally wrapped around his neck, not like the way this has got me around the arm here.
With Jimmy, I could literally see that he turned around to get this python around his body, and it wasn't a natural constricting pose, whereas this snake has got me.
I mean, look at that-- my arm's going quite red there.
I mean, I'm going to try and make a plan here.
Really got me.
One thing they got right in the movie was that the python, like many other nonvenomous snakes, are ambush... ambush animals.
They will lie in ambush for their prey.
It'll lie there, wait for the animal to come past, strike at it, bite it and hook it with those hundred needle-sharp teeth.
It then throws coils around this animal while it pulls the animal into the coils.
It then asphyxiates the animal.
Every time it breathes out, it tightens more and more and the animal dies of suffocation.
If one looks into the mouth of this python, you can see a little circular tube, and that is the extension of its epiglottis.
And it's very useful for a snake to have this because what happens is, when it swallows, that'll extend right out of the mouth.
And so it can still breathe while it's got a full mouth of antelope.
I think the snake deserves to be released now, so not to stress it too much, I'm going to release it here in the bush.
And this looks ideal here.
And as soon as I let the head go... That's it, I can feel...
I can feel the coils have immediately relaxed on me there, and the snake just wants to get away straight into the bush there.
Wow, look at that arm.
This arm's gone really quite red there.
What a relief to have that off.
This is great.
I love letting snakes go back into the bush.
It's such a nice feeling that you can do something for them as well.
It's a nice feeling for me, and hopefully for the snake.
McGILLIN: Back in anaconda country, there's someone who's trying to do good things for them as well.
Anacondas have killed and eaten people, but that fact does not deter María Muñoz.
At the ranch of El Cedral, the petite María is on the track of her favorite animal.
She works with her assistant, Ramón.
A snake longer than ten feet always requires two people for safe handling.
How many males do we have?
McGILLIN: It's the breeding season for anacondas, and María recognizes this group as small males.
She hopes they will lead her to the much larger female somewhere nearby.
The males are placed in bags to keep them out of the way.
McGILLIN: The female they find is 13 feet long.
María uses a trick to calm it down.
She dips its head in the mud so it can't see.
MUÑOZ: She was very quiet.
( speaking Spanish ) McGILLIN: For several years, María has been studying how anaconda populations here live and vary.
The tail-- I would like to know if it's a new one or she had the mark.
Let me see the cloaca.
It's a new female for us.
That means there are more than 900 anacondas... green anacondas in this ranch.
McGILLIN: Before María began her work, no one knew how many anacondas could live here.
Now, by taking blood samples for DNA, she is also getting some idea about how they are related.
But of course, she still needs to know how long these giants are.
Her personal best is nearly 20 feet, about ten feet short of the world anaconda record.
( Muñoz grunts ) McGILLIN: These are the heaviest snakes in the world, but this one is a little lighter than the 485-pound monster in the record books.
MUÑOZ: 44 point... 45 kilograms.
McGILLIN: Some snakes, like this South African tiger snake, not only constrict their prey but are also venomous.
I've got the tiger snake's favorite prey.
It is a striped skink.
Now, I'm going to bring it in closer, and you're going to notice that the tiger snake will bite and poison its prey, also wrap around it to constrict and kill.
Now, this is, of course, a dead skink, so I'm going to move it around so that the snake thinks that it's alive.
McGILLIN: The tiger snake's venom is weak, so it needs to grip the lizard firmly, not only to prevent escape but to limit the risk of damage to itself during a struggle.
Even more remarkable is an African egg-eating snake's ability to get its mouth around an egg.
All snakes can eat meals bigger than their heads.
They simply open very wide, and then ligaments allow the lower jaw to expand.
Still, the egg cannot be crushed until it reaches special bones in the spine, which can pierce the shell.
For convenience, a snake does better to eat another snake.
A king cobra is called "king" because it's a snake eater.
The mangrove snake it's attacking is only mildly venomous, no match for the king.
It's not easy for the king to judge exactly how long this meal is, but since the king is the largest venomous snake in the world, chances are the victim's tail will be reached easily and swallowed.
It's good to be the king.
So how would a snake avoid this fate?
One way would be to play dead.
This eastern hog-nosed snake is giving his best performance.
Its playacting must convince a threatening indigo snake.
There is an interesting moment of standoff, but the actor has another defensive card to play: A gland in its tail emits a smell of death to go with the gaping mouth.
It's the performance of a lifetime, and the enemy is fooled.
A snake that looks dangerous can keep predators away.
"Red next to yella will kill a fella" is a useful rhyme about a coral snake-- it is venomous.
"Red next to black is a friend of Jack" is true for a milk snake-- it mimics warning colors and only pretends to be dangerous.
A pretend head keeps the real head of a Calabar ground python safe.
The real head has a tongue that gives it away, but the deception can be good enough to cause a predator to attack the tail by mistake, and a tail is not a vital organ.
Often, the brilliant colors and patterns of a snake's skin are not a warning but a subtle camouflage, matching its surroundings, and to us, it can look beautiful.
Scales come in endless varieties of shape and structure.
In the wild, snakes are not easily seen-- a useful quality which suits these masters of ambush perfectly.
But the beauty and subtlety of snakeskin has also been their undoing for thousands of years.
Fire is traditionally used by hunters in Cameroon to expose the hiding places of aggressive rock pythons.
Entering an aardvark burrow to retrieve so vicious a snake is a risk few men will undertake.
Once this nightmare task was a test of virility, a rite of passage.
Crawling inch by inch on toes and fingers, the hunter moves toward the angry python.
( muffled talking; men respond ) McGILLIN: His companions keep track of his progress-- they may have to rescue him.
The heat is stifling.
( snake hisses ) ( man speaking local language ) McGILLIN: The hunter must squirm back through dust and biting ants, dragging a hundred pounds of python.
( man grunts ) ( men speaking local language ) McGILLIN: His companions take over.
These are the last of the python hunters left in Cameroon.
Firearms have made it easier to kill other animals for food and skins, but the meat on this snake in former times would have been essential and its skin a profitable result from such horrific effort.
As any snakes grows, it must shed its outer skin like an overtight suit.
The new scales revealed are at their best.
The cast-off skin is discarded, and with it also go most of the parasites that have attached themselves to the snake.
The regular shedding of dead skin has special significance for rattlesnakes.
Each time a rattlesnake slips out of its old skin, its rattle gains another section at the base.
The rattle is a series of loose- fitting interlocking scales that when shaken, produce a sound that warns large animals not to step on the snake.
( tail rattling ) ( rattling furiously ) Although only a warning, the rattle has been the snake's downfall.
( snakes hissing and rattling ) Their noise makes them easy to locate, and as a result, tens of thousands are killed each year.
I hate rattlesnakes.
McGILLIN: J.P. Jones sees rattlesnakes only as potential killers of people and livestock.
He's hunted them since he was a boy.
But recently, he's finding it harder to find them.
He simply can't hear them, even with the listening apparatus he designed himself.
There are rattlers around, but many are becoming quieter.
Ruthless hunting is exterminating the loudest, and a greater proportion of snakes with weak rattles are living and breeding.
Not having a loud warning, of course, makes a snake even more dangerous.
But J.P. is undaunted, and his roundup goes on, presumably until only silent rattlesnakes survive in his part of Alabama.
( insects trilling ) JONES: Yeah, I've been doing this for a long time.
78 years old, but I still enjoy it.
McGILLIN: Getting rid of snakes anywhere is never the good idea it might seem.
Farmers in Vietnam didn't value the many snakes that once lived in the paddy fields until they vanished.
The snakes were trapped for food, and the rice crop was attacked by rats.
A third of the country's crops was devastated by the rodents.
Only the return of natural predators, such as pythons, could save the farmers' livelihoods.
The government's official snake repatriator is Dr. Nguyen.
He's bringing snakes to the village where he was born.
And he knows how important it is that children as well as the farmers realize how essential these harmless snakes are to their future.
Each python released can potentially eat about a hundred rats a year.
Dr. Nguyen will release 20, among them females that could each have 20 to 80 baby pythons a year.
In the battle against rats, each snake in a paddy field is worth far more than those that are sold to be eaten.
The snakes in our world can be partners in our survival.
We're learning more about them all the time.
But there's always a new twist.
TECHNICIAN: Well, sometimes when the snakes shed, it's not a complete shed and we have to help it.
And in this case, the top scale wasn't quite off, and I think I can get it.
Now he's all done.
McGILLIN: A snake with two heads.
Something went wrong in the egg.
Such creatures are not uncommon.
Only one head can feed, but this ring-necked snake will survive happily.
It's very interesting how attached people get, or not get, to their reptilian pets.
Most people think that "How can you get attached to a snake or a lizard as compared to a fluffy kitten or a cat or dog?"
But in a way, you really do get attached to these animals, partly because you soon realize how individual they are and how the personalities differ.
By and large you do get very attached to your animals.
STRYDOM: I'm constantly surprised by snakes.
They're fascinating animals.
Just everything about them is so different to us.
They smell using their tongues, they move without any legs, they're cold-blooded, they have no ears, and they're just so interesting.
They're so different and so much you learn about them.
McGILLIN: Most of us might prefer to leave snakes to the experts.
But love them or hate them, they're an important part of our natural world.
As we shed our fears and learn more about them, we might find they're not such bad neighbors after all.
THIS PROGRAM WAS MADE POSSIBLE BY CONTRIBUTIONS TO YOUR PBS STATION FROM VIEWERS LIKE YOU.
I WAS BITTEN BY A COBRA AND ENDED UP ON A RESPIRATOR.
I'D STOPPED BREATHING.
I WAS BITTEN BY A MAMBA IN THE LEG.
A KING COBRA BITE IN THE KNEE, AND MY BLOOD PRESSURE WENT TO ZERO.
I CAN REALLY FEEL IT.
THIS AREA HERE, YOU CAN SEE HOW IT'S STOPPING THE BLOOD SUPPLY THERE.
AND THIS IS MY ARM, SO, AND I CAN HANDLE IT, I CAN WRAP IT OFF ME HERE.
IN A WAY, YOU REALLY DO GET ATTACHED TO THESE ANIMALS.
PARTLY BECAUSE YOU SOON REALIZE HOW INDIVIDUAL THEY ARE AND HOW THE PERSONALITIES DIFFER.