[gripping music] - [Narrator] Jungle exploration is epic adventure.

Scientists stare into the eyes of our closest relatives and stumble on signs of abandoned civilizations.

- That's fantastic.

- [Narrator] It's like "Planet of the Apes" meets "Indiana Jones."

- The whole thing is emerging, as it were, out of the jungle, it's fantastic!

[gripping music intensifies] [underbrush rustling] [primates chattering] - [Narrator] The jungle is revealing extraordinary secrets.

- I don't think they saw us.

- [Narrator] These discoveries can tell us where we came from and what our own future might hold.

[dramatic music] - [Announcer] This program was made possible by contributions to your PBS station from viewers like you.

Thank you.

[animals chittering] [mysterious music] - [Narrator] Scientists are heading into the jungle to see what it can tell us about ourselves.

Until very recently, we thought human beings were unique.

Do we think that taming the jungle sets us high above all other animals?

Experts are discovering we are more connected than we thought.

They've found intelligent monkeys.

They've seen culture in apes.

[apes chittering] They've even witnessed murder.

[apes squealing] And as for the idea that we can tame the jungle, well, it can tame us too.

[dramatic music] [wood creaking] [wind whooshing] Scientists believe that asking questions of the jungle and reaching out to its primates might just help us find out who we really are.

[mysterious music] [low growl roaring] First challenge, meet your beast.

[apes growling] [rain pattering] Six years ago, Italian primatologist Chloe Chippoleta began a mission in the dripping Congo forest of Central Africa.

She was determined to make contact with the Western lowland gorilla.

It was a World Wildlife Fund project to encourage ecotourism and conservation.

[insects buzzing] This is the Mountain gorilla of Rwanda.

It is well known to scientists.

But the lowland gorilla of Congo is a different species and a much tougher challenge.

[water splashes] Although you might catch a rare glimpse of them when they come out into clearings like this, they soon disappear back into the forest.

No one knows where they go or what they do.

Chloe wanted to find out by earning their trust.

[gorilla grunts] - I think the moment of maximum trust is when they come closer, stay close to you and just completely fall asleep.

You can feel pretty sure that they don't fear you at all and they are perfectly comfortable with your presence there.

- [Narrator] Other scientists have tried before and failed, but Chloe had an idea.

Not so long ago, white hunters employed local tribespeople to lead them through the jungle to this ferocious beast.

[dramatic music] Would the descendants of these tribes be prepared to help her?

[animals chattering] [upbeat percussion music] These are the Bayaka people.

They have an intimate understanding of the forest and an extraordinary ability to find their way around it.

[people chanting] When the Bayaka go hunting, they mean business.

[people singing and cheering] [upbeat percussion music] [animal grunts] [man shouting] [men chanting] [percussion music continues] [leaves rustling] [quarry growling] [hunters chattering in foreign language] [machete thuds] [birds chirping] [dramatic music] - [Narrator] Chloe asked to meet two of the Bayaka's finest trackers.

This is Nbanda and Ngombo.

[trackers chattering indistinctly] They have become Chloe's assistants.

Although the Bayaka sometimes hunt gorillas, they are generally afraid to get near them.

So Chloe's idea of tracking them and then trying to get close, must have seemed like madness.

But eventually, the Bayaka agreed to help her.

- They are very skilled Bayaka trackers, and they are fundamental in finding regularly the gorillas.

It would be totally impossible to find gorillas without the Bayaka.

- [Narrator] The plan was to attempt to follow one group of gorillas every day from the tracks and traces they left behind.

Nobody but the Bayaka could achieve this.

At first, all they'd get is the occasional glimpse.

[suspenseful music] If Chloe's mission succeeds, it could open a door for dramatic new discoveries.

[snake hisses] It happened before in Tanzania, East Africa.

It's where our closest relative lives, the chimpanzee.

When chimps let people into their lives, experts made one of the most important breakthroughs in the history of science.

[burgeoning music] They saw chimps rip off branches and shape them.

[chimps chattering] They made fishing rods to catch juicy termites.

Other chimps were using rocks to open nuts.

The problem was, animals weren't meant to be able to make and use tools.

Only we did that.

[dramatic music] Not anymore.

[nut shatters] [tools banging] Chimps evolved this skill to get at the forest's richest food.

This was a huge blow to ideas of human uniqueness, but it was just the beginning.

The orangutan of Borneo was the experts' next target, but there seemed no great intelligence lurking here.

This is an orang's method of opening a termite's nest.

[orangutan squeals] Yet orphaned orangs showed a clever ability to mimic their human foster parents.

[burgeoning music] Finally, another breakthrough.

A stick, a stinging pod, a home-made chopstick.

Tool use isn't a human skill, it's a great ape skill.

[dramatic music] Chloe's team in Congo is making progress.

They find signs of gorillas every day and are able to keep up with the gorillas' movements.

A gorilla was here.

A knuckle print.

- It's the foot of the silverback.

[animals squawking and chittering] The Bayaka are looking for the tracks of the gorillas now.

We've found the nest, so we're looking for today's tracks.

- [Narrator] The technical term for what this team is trying to achieve is habituation.

- Animals get habituated when they ignore the human presence, when they don't react to human presence, we don't know how much they can ignore it.

We are three people following them everyday and that cannot totally be ignored.

- [Narrator] It's a relentless task.

- Christmas day, New Year's Eve, Independence Day, everyday.

[Chloe chuckles] [suspenseful music] - [Narrator] When they eventually get close, the last thing they want is to surprise the gorillas.

Ngombo recognizes an adult gorilla calling to a youngster.

[gorilla grunting] [gorilla grunting] It's a tense moment because gorillas can be dangerous if they're frightened.

[gorilla grunting] It's crucial to the process that the gorillas know the people are close by and learn that they're harmless.

[Ngombo clicks tongue] They deliberately make an unthreatening noise.

[gorilla grunting] [Ngombo clicks tongue] [leaves rustling] And the sound of an animal grazing.

[leaves ripping and crunching] [gorilla chatters] [dramatic music] A silverback, and he didn't run.

It's progress.

There's a young male too.

[gorilla chatters] The Bayaka don't want clumsy Westerners destroying months of hard work.

- They want to leave us here.

This is not normally what happens.

- [Dave] Why do they want to leave us here?

- Because you make too much noise and you're slow.

[laughs] - [Narrator] The team is determined to carry on this desperately slow process for as long as it takes.

While Chloe is trying to get to know her gorillas, on the other side of the world, in Brazil, primates have smashed down another assumption of our uniqueness.

This time, it wasn't even a great ape.

[mysterious music] [birds squawking] This place is called Green Wing Valley.

And here, scientists stumbled on something that looks like a stone-age workshop, [animals chittering] [birds squawking] with tools that are obviously still in use.

[mysterious music] This lowly black-capped capuchin monkey is the only primate here, and it's frustrated.

[birds squawking] These pods contain palm nuts, and that's the best food around.

The macaws can break them open with their beaks.

The monkeys can't.

[macaw chirping] [wings flapping] [dramatic music] The capuchins pick the pods anyway.

It's the start of an amazing process.

They tap them to see how ripe they are.

[monkey knocking] [monkey screeching] [animals chittering] [dramatic music] This one is just right.

A bite to the top, and the capuchin can drink the liquid inside.

But they seem to give up on getting the nut out.

In fact, they're giving the pods a few days to dry out.

[monkey knocking] One day, observers saw capuchins carry the dry pods to the strange rocks.

They placed them carefully and prepared for an Olympian task.

[heroic music] [nuts clacking] Then, they did something no monkey was thought capable of doing.

[heroic music] [triumphant music] These rocks can weigh as much as a capuchin itself.

[rocks banging] They've been carried from the river from over a mile away.

[triumphant music] If a primitive monkey can come up with such a complex kind of tool-use, it's impossible to guess what other surprises the jungle is going to offer us.

[triumphant music] [monkey squealing] And there's more to the surprise.

It looks like capuchins aren't born with the skill.

The young need to learn it, probably from their parents.

[birds chirping] This way of passing on skills is yet another body blow to the idea that humans are separate from other creatures because this is the first step in developing culture.

[monkeys chittering] Chimps have taken things much further.

Some groups open nuts using stones, but for exactly the same job, another uses wooden clubs, locally different ways of doing the same thing.

This is culture and a window on the origins of our own complex world.

[dramatic music] [whistle tooting] [people chanting] [rock bangs] [crowd cheering] It's possible that the great complexity of human culture had its beginnings in scenes like this, tool using skills passed from adult to young.

[dramatic music] Back in the Congo, the tracking continues.

When they stop for a rest, Chloe learns about the Bayaka culture.

[Chloe speaks in foreign language] [Nbanda and Ngombo speaking foreign language] Sharpened teeth are the equivalent of body piercing or tattoos in our own culture.

[Chloe speaking in foreign language] - Mm-hmm.

[Ngombo and Nbanda speaking foreign language] [Chloe laughs] - Whoa!

Okay?

- Mm-hmm.

[speaks foreign language] [Chloe speaks foreign language] - Tired of running for a minute.

[Nbanda and Ngombo chattering] Okay, that's how you do it.

You put the wood, the stick in the mouth of the person.

[Chloe laughs] And you have to hold the head.

[Ngombo and Chloe speaking foreign language] One is the knife and the other is another piece of metal.

It can be another knife, a file.

And then you just sculpt on one side, then the other.

[Chloe speaks foreign language] [all laugh] The reason why they cut their teeth up until today is because it's something that their Great Grandfathers were doing and the Bayaka have always done it.

And they are Bayaka, and they are always going to do things that the Bayaka have always done.

[Nbanda and Ngombo chattering] - [Narrator] One Bayaka tradition that Chloe hopes to change is their mistrust of gorillas.

If the team can get gorillas used to people, then tourists will come.

There will be jobs for local people and a good reason to conserve the gorillas.

- It is in this part of the forest that it's more open that the traces become more difficult to find because there are not many leaves on the ground that the gorilla can step and leave a sign.

Whereas the Bayaka, they have a knowledge of the forest, of how it should be when it is not perturbed, where no animal has gone by.

And so when they walk in the forest, they can see when leaves have been turned, or a leaf, a shrub has been bent.

When an animal has passed by, the herb will turn and show this side here, and I can see that an animal has passed by, and I can also detect which direction.

So, of course, we could see little things like this too with a lot of experience.

But first, we wouldn't be able to keep up with them, we would spot one and that's it.

[insects chirping] [animals chittering] They can't even explain how they find the gorillas, the animals, in the forest, they just know it, they look for them and find them.

- [Narrator] For the moment the gorillas keep running away and the Bayaka keep following.

There are signs that other animals passed this way.

- Big elephant tick - [Narrator] It's a tick from a forest elephant.

- Quite full.

- [Narrator] Full of blood.

[Chloe speaking foreign language] - He thinks it is very tired.

[laughs] He thinks it's really very full, now it's gotta rest.

[Chloe laughs] - [Narrator] Chloe, Ngombo and Nbanda have been catching glimpses of gorillas, enough to name a few of them.

[suspenseful music] Now, they're about to have a breakthrough.

- When the vegetation is dense, we don't sneak behind them.

We try to always see them and so that they also can see us.

We don't like to get too close in the dense vegetation.

[gorillas grunting in distance] [fruit pattering] - [Narrator] Fruit is showering down to the forest floor.

Moustached monkeys are clumsy eaters.

[Nbanda speaks foreign language] Red river hogs have come to gorge on the windfall, [suspenseful music] and so have the gorillas.

[animals chittering] [suspenseful music] Perhaps the noise or smell of the pigs is masking the presence of humans.

[gorilla grumbles] The river hogs are stealing all the fruit.

[hog grunting] The young male wants to show who's boss.

[gorilla huffing] The hogs just ignore him.

[gorilla grunting] The silverback is a different matter.

- Ndimbalimba went barking towards the pigs, but you could see that the pigs weren't very intimidated by the little gorilla.

And then Mlima charged a little bit and barked to the pigs too, and then they left.

I don't think they saw us.

- [Narrator] With the naivete of youth, the young gorilla moves closer to the people.

[underbrush rustling] He's intrigued.

[gorilla grunting] [underbrush rustling] [Chloe chuckles] [suspenseful music] The silverback has noticed what's going on, [suspenseful music continues] and he doesn't like it.

[suspenseful music building] [underbrush rustling] He's made his point, without trying to harm anyone.

[group snickering] [dreamy music] - I think it was a warning to both us and his son to stop what was happening and that very close interaction.

He just had to tell his... How do you say?

Reprimand us from that.

- [Narrator] There's a long way to go before Chloe and the gorillas can sit close by one another in a spirit of mutual trust.

[Chloe chuckles] [gorilla grunting] We aren't just learning things about our jungle past from other primates.

In true Indiana Jones style, archaeologists are hunting here for signs of humans, not jungle tribes, but ancient civilizations.

They believe that unlocking the secrets of the past may help us discover something about our own future.

[Rene chattering indistinctly] Rene Munoz and Charles Golden have come to the jungles of Guatemala looking for a lost city.

An old photograph is their only clue that the jungle is hiding a great find.

- It really is tremendous thing to find a building like this.

And to find one in sort of this area and this isolated still intact is just a wonderful thing.

- [Narrator] If they can find the site, they may discover what happened to the people who lived there.

Golden is directing the first archaeological survey of this remote region.

For years, civil war kept archaeologists away from this area.

- It looks like you have two figures surrounded by a ring of... - Rotoglyphs.

- Hieroglyphics.

- [Narrator] This ancient symbol may be telling them something, but what?

[arduous music] [underbrush rustling] [guides chattering in foreign language] The jungle is so dense, so wild, it seems impossible that there could once have been buildings here, let alone a thriving civilization.

[monkey grunting] [arduous music continues] Even the plants are inhospitable.

- This Escoba Palm will go right through your hand like a hypodermic needle.

It'll puncture the joint and give you a nasty infection too.

Definitely don't want to touch this.

- See this wall Charles?

- Is this the doorway here?

- I think so.

We must be getting close.

[dangerous music] - [Narrator] This may be dense jungle, but there are signs of ancient people everywhere.

[dramatic music] - That's fantastic.

- It is an amazing thing.

[dramatic music] - [Narrator] Whoever built this worshiped some kind of God or spirit.

It may be more than 1,000 years old.

[mysterious music] Finally, they find the mysterious building.

A reception hall for some kind of noble, a place of power and prestige.

[dramatic music] - This whole area would have been plastered.

The floors would have been brilliant white, probably.

And the outside of the building would have been also plastered, maybe painted red.

- [Narrator] A grand city begins to take shape.

- Within this plaza, there's six or seven other structures similar to this one, and then raised up above the other remaining four or five structures.

It would have been very impressive.

- [Narrator] These people were way ahead of Europe at the time.

- Europe was in the middle of the Dark Ages, the Roman Empire had fallen, there was no really great civilization.

People still thought that the sun circled the earth.

- [Narrator] This place is one more bit of evidence that hundreds or even thousands of square miles of what is now forest was once cleared to feed a great population.

And this is but a fragment of the Maya civilization.

[archaic music] 100 miles away, Tikal was one of its great cities, home to more than 50,000 people.

[archaic music continues] As the Maya people climbed these steps, the edge of the forest was far out of sight.

So where did the people go?

Why did the jungle return?

[wood creaking] [leaves rustling] [animals chittering] [archaic music] [monkey chittering] [archaic music continues] How could such a resourceful people allow the jungle to reclaim their land and destroy their civilization?

[transitory music] A similar mystery lies halfway across the globe in another jungle in South East Asia.

Here in Cambodia, a tantalizing legend haunted explorers for years.

[dramatic music] It was said that a warrior king out on a hunting trip in the forest found something no one knew was there, [dramatic music] the ruins of a glorious city.

[impressive music] [elephant grunts] Its existence wasn't proven to Western science until the 1800s.

It's the civilization of Angkor.

[mysterious music] Archaeologist Charles Higham has spent 30 years trying to unravel why this place, like the Maya's great cities, became a ghost town.

What huge catastrophe befell the people living here?

Is there a warning to us in what they left behind?

- Well, this view from on top of the back Ang Hill gives you the best possible image of what Angkor must once have been like because you can see all the main features of this great complex.

Over on the right-hand side there, you can make out the water of the western barai, or reservoir, which would once have arrested and controlled the water coming down from the hills behind me.

And over there, through the trees, we can just see the five sand stone towers of Angkor Wat.

[overwhelming music] What we don't know is what happened to all the people.

The answer, I think, lies out there, in the jungle, because what we've got to find is where people were living, how many of them were there, and what they were doing.

- [Narrator] Charles heads deep into the forest for clues.

- Even here, 30 kilometers from the walled city, it's still possible to come across signs that people once lived here.

And this is exactly the sort of thing we're looking for, cut sandstone.

And then a second and a third.

The whole thing is emerging, as it were, out of the jungle.

It's fantastic!

You can see here a human form, a set of shoulders, a body.

Perhaps somewhere buried deep here, there's the head to go with it.

Over there, the beginnings of a wall.

The more we track through these trackless jungles, the more of these really quite remarkable sites we're beginning to find.

- [Narrator] These extraordinary people even paved the river.

[water trickling] Charles and others believe the sheer size of this place may have been the key to its collapse.

But no one knew just how big it was until space-age technology offered a new perspective.

- [Flight Controller] Zero.

Ignition.

Lift off.

[engines roaring] [dramatic music] [serene music] - [Narrator] Infrared imaging technology can cut straight through the jungle canopy, revealing the city in all its glory.

The results excelled even Charles' expectations.

At about 386 square miles, Angkor was bigger than modern New York, the largest pre-industrial urban area the world has ever known.

Once experts had discovered the scale of this place, the reason for its collapse was staring them in the face.

[dramatic music] - [Charles Higham] Only now are we beginning to realize the extraordinary extent of Angkor, how the population spread way beyond the city walls.

[birds chirping] [expansive music] - [Narrator] The city's growth became unstoppable and its people would have constantly cut back the jungle to create more land for agriculture.

No one would have known that this clearance couldn't go on forever, that eventually disaster would strike this magnificent civilization.

A million people were on the brink.

We can guess how tragedy began to strike because we are still repeating the story today.

[wood cracking] Rainforest controls the climate for many miles around.

When the trees are gone, burning sun scorches bare earth and the temperature rises.

[saw buzzing] [dramatic music] Terrible drought and fire follow.

[wood cracking] The jungle is a vast sponge that soaks up masses of water.

[thunder rumbles] With no sponge, rains become floods which destroy everything in their path.

Both Angkor and the Maya civilization of Central America grew until they wrecked their own environments.

- [Charles Higham] There was a population growth and people began to cut down more trees and sedimentation began.

The great canals, the rivers, began to choke and silt up.

- [Narrator] The civilizations descended into war and bloodshed.

- There was fighting over resources.

There was internal divisions and conflict.

The whole social fabric began to disintegrate.

And before long, this huge city was abandoned and the jungle began to reclaim its own.

[slithering roots crackle] - [Narrator] So in this story, for once, the jungle won and the humans lost.

For all their searching, scientists have not discovered another creature capable of destroying its own environment the way we humans can.

[slithering roots crackling] But are we also unique in our readiness to start wars and destroy our own kind?

To find an answer to these dark questions, scientists have gone back to our closest relative, the chimpanzee.

[chimpanzee vocalizing] [chimpanzee barking] Primatologist David Watts from Yale University has been coming to the forests of Uganda for 12 years.

He's looking for the origins of politics and warfare, in chimps.

- Many people tend to make a distinction between humans and animals, but they forget that humans are animals.

They could potentially tell us a lot about human history, and help us better to understand ourselves now.

[dramatic music] [chimpanzee squawking and grunting] [chimpanzee grunts] - [Narrator] We didn't evolve directly from chimps, but our own ancestors were similar.

[chimpanzee vocalizing] David follows the chimps every day for weeks on end, and often, he'll see them prepare to hunt Colobus monkeys.

It's a chilling and all too human display of organized aggression.

[tense music] [chimpanzees grunting] [monkey squealing] [chimpanzees grunting and squawking] David has watched more than 100 hunts, but he doesn't see it a mindless mass attack.

The chimps don't actually need the meat.

The whole thing is about politics.

- [David] They are all collaborating in this.

And male chimpanzees, especially, are very given to that kind of collaboration.

[chimps squawking and chittering] [chimpanzee grunting] [chimpanzees screeching] [monkey squealing] [chimpanzee barking] [monkey squealing] - [Narrator] Chimp societies are built around friendships and alliances.

Hunts are about strengthening these bonds.

[chimpanzees squawking and chattering] David's seen that the meat is shared with allies and kept from enemies.

It's a gruesome form of politics.

Many people have seen chimps hunt, but David has seen them go one step further.

[screech echoes] He's seen that we are not the only species that will go out looking for our own kind with the intention of murder.

[chimpanzees squeal and bark] [calm music] It began like any other day.

David was following a group of male chimps, capturing their behavior on tape.

It appeared to be the usual story, preparation for a Colobus hunt.

[chimpanzees grunting] But this was no normal hunting party.

These chimps were like a group of soldiers on patrol, looking for their own kind.

[chimpanzees chittering] [chimpanzee squealing] - [David] At first I didn't know that it was an adult male chimp who was up a fairly small tree and many Ngogo males surrounding this tree on the ground screaming and just incredible commotion.

Then several Ngogo males started to climb up this tree.

The male who was up there tried to climb from there into an adjacent tree, but the tree he was in was just too small to bear the weight of about four adult male chimps.

[chimpanzees screeching] [branch cracks] And the top broke and he crashed to the ground, at which, he tried to run off, but all the others ran off after him.

[chimpanzees screeching] And by the time we got to where they'd stopped, they had caught him.

[chimpanzees screeching] He had up to 15, 20 other chimps piling on top of him.

[chimpanzees screeching] [dramatic music] [chimpanzees squawking and grunting] - [Narrator] Did we inherit premeditated murder from our distant ancestors and take it with us from the forest?

Is this the jungle's darkest secret?

It took great skills of planning and co-operation to co-ordinate such a hunt, and in these skills lie the seeds of hope.

[chimpanzee screeches] It's these same abilities that lead to great achievements.

This is what has always set us apart.

Trade, politics, society, they are the building blocks of our great civilizations.

And David believes that there is one fundamental way that humans are unique.

- [David] I don't think that they have anything like the ethical systems that humans do, or can understand the consequences of what they're doing in the way that humans ought to be able to understand the consequences.

[dramatic music] - [Narrator] If humans understand consequences, they can free themselves from the laws of the jungle and choose what they do.

Perhaps Chloe's task of getting close to gorillas embodies that moral uniqueness.

After all, we're the only species that can work to preserve another.

- Here he is, just arrived now.

- [Narrator] It's taken Chloe and the Bayaka six long years just to get the lowland Gorillas to accept their presence.

[Chloe whispering indistinctly] - He went back to sleep.

Right behind... [Ngombo and Nbanda whispering in foreign language] - [Narrator] They say a true sign of friendship is falling asleep in company.

[tranquil music] - [Chloe] They've just had a very bad night because it's been raining all night.

And so they've found a new place, a bit in the sun, and they're taking a rest.

The juvenile's still sleeping, but the male's just walked off eating behind there.

[tranquil music] - [Chloe] It takes a lot of trust for them to be sleeping so close to us.

He's sleeping in full visibility, we are within 10 meters.

And for him to just decide to sleep in that spot, we didn't find him there, he came and choose that place and lie down and closed his eyes after looking at us, so... - [Narrator] We've come a long way since these gorillas were seen as terrifying monsters.

The silverback is getting at termites by shaking chunks of their nest into his hand.

It's not quite tool-use, but it gets the job done.

- [Chloe] He's just playing.

He's just spitting a little bit.

- [Narrator] His son hasn't quite got the hang of it.

[tranquil music] He tries another tactic.

This close-up view is a jungle first.

It's in these kinds of intimate moments that we've learned so much about ourselves from our relatives.

[Chloe laughing] [tranquil music continues] Chloe and her skilled Bayaka trackers have finally opened a brand new door.

It's taken extraordinary commitment.

- They've had some of us following them everyday for six years of their life.

Christmas day, New Year's Eve, Independence day, everyday.

[Chloe chuckles] [Ngombo murmurs indistinctly] [tranquil music continues] To be able to contact them regularly, the Bayaka were fundamental in this process.

It's only thanks to their skills in finding them everyday that we succeeded in habituating them.

- [Narrator] It's been well worth the effort to turn ancient enemies into new friends.

- But I think we have taught them, to the Bayaka, also something, because they never thought that there could be this kind of relationship with the animals of the forest.

[gorilla vocalizing] - [Narrator] Exploring the jungle can give us an insight into how we became the extraordinary species that we are, and it's shown that we are unique, just not in the way we thought.

[group chattering and laughing] Only we can reach out to conserve another species, like Chloe has.

[gorilla exhales softly] - [Announcer] This program was made possible by contributions to your PBS station from viewers like you.

Thank you.

- [Narrator] Primatologist David Watts has recorded a lot of interesting chimp behavior in the field, [chimpanzees squawking] [bees buzzing] but this is one of his favorites.

[chimpanzees chattering] [bees buzzing] It's a raid on a beehive.

Honey is one of the chimpanzees favorite foods, and they're willing to withstand bee stings and aggression from other chimps in order to get a fix.

Sometimes, a twig is used to fish honey from a hive.

But these renegades forego at tool and thrust their arms into the tree hollow to grab what they can.

[bees buzzing] The first few to dig in get most of the honey.

But that doesn't deter all of the late arrivals.

They reach deep into the tree, searching for a piece, even a tiny morsel of the treasured treat.

[bright music]