0:00:02 > 0:00:05The world is full of extraordinary animals.
0:00:08 > 0:00:10But how well do we really understand them?
0:00:12 > 0:00:14How do they really think and feel?
0:00:15 > 0:00:20To find out, a team of spy creatures is going undercover.
0:00:22 > 0:00:24They not only look like part of the family,
0:00:24 > 0:00:26they behave like them, too.
0:00:28 > 0:00:32Armed with the latest camera technology,
0:00:32 > 0:00:34they are going to travel the globe...
0:00:35 > 0:00:39..to understand the true nature of the animals they meet
0:00:39 > 0:00:43and reveal how intelligent they really are...
0:00:46 > 0:00:48..how badly behaved they can be...
0:00:51 > 0:00:53..how important friendship is to them...
0:00:55 > 0:00:58..and if it's possible that they can truly love each other.
0:01:00 > 0:01:04What they discover will change our perception of animals for ever.
0:01:07 > 0:01:11Perhaps they are more like us than we ever believed possible.
0:01:22 > 0:01:25When it comes to solving life's problems,
0:01:25 > 0:01:27just how clever can animals be?
0:01:33 > 0:01:38In the forest in Borneo lives one of our closest animal relatives,
0:01:38 > 0:01:39the orang-utan.
0:01:44 > 0:01:47These great apes share 97% of our DNA.
0:01:56 > 0:01:58They're one of the most intelligent animals on Earth.
0:02:00 > 0:02:03To film the behaviour of these shrewd primates
0:02:03 > 0:02:06requires an exceptionally lifelike spy creature.
0:02:12 > 0:02:14To be totally convincing,
0:02:14 > 0:02:17Spy Orang-utan must mimic their facial expressions.
0:02:20 > 0:02:24Rather than bare her teeth, she needs to appear friendly.
0:02:27 > 0:02:29By sending out the right signals,
0:02:29 > 0:02:31she soon draws attention.
0:02:35 > 0:02:38Adult males are always interested in any new female.
0:02:42 > 0:02:45But he needs some convincing that all is quite what it seems.
0:02:48 > 0:02:50Spy Orang-utan pouts her mouth,
0:02:50 > 0:02:52a sign she's not a threat.
0:02:54 > 0:02:59As news gets around, a young male comes to investigate,
0:02:59 > 0:03:01and he, too, seems unsure.
0:03:03 > 0:03:05Time for some careful reflection.
0:03:10 > 0:03:12He keeps a safe distance,
0:03:12 > 0:03:16and finds an imaginative way to test the spy creature's reactions.
0:03:21 > 0:03:24It's a somewhat unorthodox way to make new friends.
0:03:38 > 0:03:42Solving problems creatively is proof of a clever mind.
0:03:47 > 0:03:51Over time, as more orang-utans visit the strange new creature,
0:03:51 > 0:03:54confidence grows that she's not a threat.
0:03:58 > 0:04:00One youngster seems especially curious.
0:04:11 > 0:04:13Young orang-utans learn
0:04:13 > 0:04:16by constantly interrogating their surroundings, and everything in it.
0:04:19 > 0:04:22Spy Orang-utan captures a unique view
0:04:22 > 0:04:25of an intelligent young mind developing.
0:04:46 > 0:04:49Curiosity satisfied, he heads back.
0:04:50 > 0:04:52Among these orang-utans,
0:04:52 > 0:04:56the thirst for knowledge has inspired some astonishing behaviour.
0:04:59 > 0:05:01Careful to keep her baby dry,
0:05:01 > 0:05:05the mother leaves the jungle to visit an old research outpost.
0:05:11 > 0:05:13This is the human world,
0:05:13 > 0:05:16a treasure trove for enquiring minds.
0:05:23 > 0:05:25She quietly helps herself.
0:05:27 > 0:05:29A bar of soap.
0:05:39 > 0:05:41She carries her find in her mouth back to the forest...
0:05:56 > 0:05:58..and joins a friend.
0:06:03 > 0:06:06They appear to use the soap just as we would.
0:06:13 > 0:06:15Around 40 years ago,
0:06:15 > 0:06:18rescued orang-utans released here learned to use soap
0:06:18 > 0:06:21by watching local people washing in the river.
0:06:21 > 0:06:25But, remarkably, these orang-utans were born in the wild,
0:06:25 > 0:06:28so the idea has spread among the wild population.
0:06:41 > 0:06:44The sharing of the soap suggests how new orang-utans
0:06:44 > 0:06:46may have learned the technique.
0:06:48 > 0:06:52It's become a form of animal culture, passed on to the young,
0:06:52 > 0:06:55something only seen among a few intelligent species.
0:06:58 > 0:07:00Why they are so keen to lather up
0:07:00 > 0:07:03is intriguing and not completely understood.
0:07:05 > 0:07:08But then, nearby, a female does something
0:07:08 > 0:07:11that might shed light on this extraordinary behaviour.
0:07:11 > 0:07:13She chews a piece of bark...
0:07:16 > 0:07:19..and creates a frothy lather in her mouth,
0:07:19 > 0:07:20just like soap suds.
0:07:24 > 0:07:26Rubbing it on her arm,
0:07:26 > 0:07:29she makes the same movements as she would if washing with soap...
0:07:36 > 0:07:38..but then starts to eat it.
0:07:40 > 0:07:44Orang-utans are known to use medicinal leaves in similar ways.
0:07:44 > 0:07:47So perhaps the bark has therapeutic qualities, too.
0:07:49 > 0:07:52Maybe soap washing caught on so easily
0:07:52 > 0:07:54because it mirrored their natural behaviour.
0:07:57 > 0:07:59They also eat the suds, but strangely,
0:07:59 > 0:08:01they seem to enjoy the taste.
0:08:05 > 0:08:08It doesn't harm them in any way.
0:08:08 > 0:08:10Perhaps it aids their digestion, too.
0:08:13 > 0:08:17And now Spy Orang-utan gives it a try...
0:08:19 > 0:08:21..much to the real one's fascination.
0:08:23 > 0:08:27Intelligent curiosity is vital for orang-utan survival
0:08:27 > 0:08:29in a complex jungle world.
0:08:36 > 0:08:39In the cold and harsh conditions of Alaska,
0:08:39 > 0:08:42animals also rely on their wits to stay alive.
0:08:44 > 0:08:49Here, sea otters gather together in congregations known as rafts.
0:08:49 > 0:08:52They are notoriously difficult to approach.
0:08:56 > 0:09:01So Spy Sea Otter offers the best chance to infiltrate their world.
0:09:09 > 0:09:10He approaches slowly...
0:09:18 > 0:09:20..and soon captures some of the closest
0:09:20 > 0:09:22and most intimate views possible.
0:09:44 > 0:09:45Happy he's harmless,
0:09:45 > 0:09:48the otter gets on with his daily routine.
0:09:51 > 0:09:53Wherever he goes,
0:09:53 > 0:09:55Spy Otter keeps a spying eye on him.
0:09:57 > 0:10:00Sea otters spend up to 50% of their time feeding,
0:10:00 > 0:10:04catching seafood delicacies such as clams and crabs.
0:10:09 > 0:10:09But some shells are just too tough for their teeth to crack.
0:10:09 > 0:10:12But some shells are just too tough for their teeth to crack.
0:10:15 > 0:10:17This is where their ingenuity comes in.
0:10:26 > 0:10:28Stones are dredged from the seabed...
0:10:30 > 0:10:33..then placed on their chests as anvils.
0:10:37 > 0:10:39He can then crack even the toughest shell.
0:11:10 > 0:11:12It's a brilliant solution,
0:11:12 > 0:11:15but a mother with a newborn faces a problem.
0:11:16 > 0:11:18How to feed with a baby on board?
0:11:29 > 0:11:32Newborn otters are covered with soft, downy fur
0:11:32 > 0:11:34to keep them warm and buoyant.
0:11:36 > 0:11:39It takes three months to gain the waterproof adult fur
0:11:39 > 0:11:40needed to dive underwater.
0:11:42 > 0:11:44So, when he's wet and bedraggled,
0:11:44 > 0:11:48the mother grooms his fur and blows in air to keep him dry and buoyant.
0:12:02 > 0:12:05Having spruced him up into a floating fuzzball,
0:12:05 > 0:12:08she confidently leaves him to bob about on his own.
0:12:12 > 0:12:14She's now free to dive for food...
0:12:20 > 0:12:21..leaving baby asleep
0:12:21 > 0:12:23in his furry flotation suit.
0:12:38 > 0:12:40When he awakes, he finds his mother has gone.
0:12:47 > 0:12:48He swims to reach her,
0:12:48 > 0:12:50but he's now fighting the tide.
0:12:58 > 0:13:00But his mother must eat while she can.
0:13:00 > 0:13:03The survival of both depends on it.
0:13:10 > 0:13:12The baby may be struggling,
0:13:12 > 0:13:14but here, mothers believe in tough love.
0:13:16 > 0:13:19She can't miss the opportunity to feed.
0:13:23 > 0:13:25No matter how vigorously her baby swims,
0:13:25 > 0:13:27the current carries him away.
0:13:37 > 0:13:39But his mother is smarter and more caring than she seems.
0:13:50 > 0:13:52Far from being neglectful,
0:13:52 > 0:13:54she's teaching her baby a vital survival lesson.
0:14:01 > 0:14:03He's been born into a tough world.
0:14:03 > 0:14:05These sea swells are nothing
0:14:05 > 0:14:07compared with what he'll face in the future.
0:14:12 > 0:14:15Intelligent animals spend a lot of time teaching their youngsters.
0:14:17 > 0:14:19It's how they pass on vital skills.
0:14:24 > 0:14:24Now another lesson.
0:14:24 > 0:14:26Now another lesson.
0:14:26 > 0:14:28In rough weather, sea otters
0:14:28 > 0:14:29wrap themselves in kelp
0:14:29 > 0:14:31to use as an anchor.
0:14:37 > 0:14:40Sometimes, it helps to cosy up with someone else.
0:14:47 > 0:14:49Spy Otter tries it out.
0:15:00 > 0:15:02Clearly, this is harder than it looks.
0:15:07 > 0:15:09In this harsh environment,
0:15:09 > 0:15:12the otters' intelligence helps them eke out a living.
0:15:19 > 0:15:21The arid forests of north-east Brazil
0:15:21 > 0:15:24could hardly be more different,
0:15:24 > 0:15:27but here, too, necessity is the mother of invention.
0:15:28 > 0:15:32It's so dry, bearded capuchins find little in the way of fruit.
0:15:34 > 0:15:37Instead, they have to make do with dried seeds and nuts.
0:15:39 > 0:15:42But these nuts have incredibly hard shells.
0:15:45 > 0:15:48To crack them open, they use stones as tools,
0:15:48 > 0:15:51some almost as heavy as they are.
0:15:52 > 0:15:54It's a cultural tradition
0:15:54 > 0:15:57that's thought to be at least 700 years old.
0:16:00 > 0:16:04Spy Rock stakes out their favourite nut-cracking site.
0:16:12 > 0:16:16It takes both skill and intelligence to perfect the technique.
0:16:19 > 0:16:21But the rewards are great...
0:16:23 > 0:16:25..even if a little bitter.
0:16:28 > 0:16:31Rolling the nut removes the unpleasant pith.
0:16:38 > 0:16:41These techniques can take three years or more to truly master.
0:16:55 > 0:16:58First, he uses smell to select the perfect nut.
0:17:04 > 0:17:06Then looks for a good spot,
0:17:06 > 0:17:08one where it won't roll away.
0:17:15 > 0:17:17It's a frustrating business.
0:17:21 > 0:17:22Success!
0:17:27 > 0:17:29But it's never that easy.
0:17:29 > 0:17:31The branch isn't a good choice.
0:17:43 > 0:17:45He's learning the hard way
0:17:45 > 0:17:47that wood is far too bouncy to work as an anvil.
0:18:03 > 0:18:06There is only so much frustration any monkey can take.
0:18:09 > 0:18:11Time to think this through.
0:18:14 > 0:18:16At around 18 months old,
0:18:16 > 0:18:20young monkeys start seriously practising using stone tools.
0:18:22 > 0:18:26Spy Rock is designed to be the monkey's favourite shape and weight.
0:18:26 > 0:18:29But it's far too heavy for a little one to lift.
0:18:31 > 0:18:32It may capture his interest...
0:18:34 > 0:18:36..but it's no use to him at all.
0:18:44 > 0:18:46But could it work for someone else?
0:19:08 > 0:19:11Spy Rock may be the best weight for the job,
0:19:11 > 0:19:13but it takes all his strength to lift it.
0:19:19 > 0:19:22This time, he's learned from his mistakes
0:19:22 > 0:19:25and picks an anvil used by the more experienced monkeys.
0:19:26 > 0:19:28But will it do the trick?
0:20:15 > 0:20:17He's done it.
0:20:19 > 0:20:22It's a significant moment.
0:20:22 > 0:20:24Capuchins only survive here by being smart
0:20:24 > 0:20:27and learning from trial and error.
0:20:27 > 0:20:30But such intelligence is not confined to primates.
0:20:34 > 0:20:36In the cloud forests of New Caledonia,
0:20:36 > 0:20:38an island east of Australia,
0:20:38 > 0:20:41lives one of the world's cleverest birds...
0:20:45 > 0:20:47..the New Caledonian crow.
0:20:49 > 0:20:53These crafty characters have many ingenious ways of finding a meal.
0:20:57 > 0:21:01Spy Crow is here to film just what these super-smart birds can do.
0:21:03 > 0:21:06This one has found the fruit of a candlenut tree.
0:21:08 > 0:21:10It's a hard nut to crack,
0:21:10 > 0:21:12and her beak is not up to the job.
0:21:13 > 0:21:16Fortunately, she has an ingenious solution.
0:21:18 > 0:21:20She places it in the cleft of a tree.
0:21:22 > 0:21:24One with a stone directly beneath.
0:21:25 > 0:21:28Spy Crow is in one of the few secret spots
0:21:28 > 0:21:29where a branch of the correct height
0:21:29 > 0:21:31is perfectly aligned with a rock below.
0:21:35 > 0:21:38The crow takes aim with meticulous precision.
0:21:41 > 0:21:43Then, bombs away!
0:21:49 > 0:21:51But these are seriously tough nuts.
0:21:57 > 0:22:00So around here, crows don't give up easily.
0:22:11 > 0:22:13This time, she's cracked it.
0:22:16 > 0:22:19But the crow's intelligence doesn't end here.
0:22:19 > 0:22:22To enjoy the opportunities the forest has to offer,
0:22:22 > 0:22:23it pays to be creative.
0:22:26 > 0:22:30Even the rotting trunks of candlenut trees contain hidden treasures.
0:22:32 > 0:22:34It just takes a bit of know-how to find them.
0:22:37 > 0:22:40A fat and juicy longhorned beetle larva.
0:22:42 > 0:22:45To capture the crow's ingenious hunting skills,
0:22:45 > 0:22:47a Spy Grub is concealed in the rotten wood.
0:23:00 > 0:23:03The crow's keen vision soon pinpoints the real larva,
0:23:03 > 0:23:05but it won't be easy to reach.
0:23:09 > 0:23:12However, this is a bird with a plan.
0:23:17 > 0:23:19She selects a tool of the perfect length.
0:23:23 > 0:23:27Under Spy Crow's watchful eye, she probes deep into the hole...
0:23:32 > 0:23:35..dextrously aiming for the larva's jaws.
0:23:36 > 0:23:39Its bite seals its fate.
0:23:43 > 0:23:45The crow disarms the larva
0:23:45 > 0:23:46by removing its powerful jaws.
0:23:51 > 0:23:53The grubs are so large and nutritious,
0:23:53 > 0:23:55a few a day is all she needs.
0:23:57 > 0:23:59Caledonian crows acquire their knowledge
0:23:59 > 0:24:02through both practice and learning from others.
0:24:04 > 0:24:07The crow calls down a young family member
0:24:07 > 0:24:08for some one-to-one tuition.
0:24:08 > 0:24:10CROW CAWS
0:24:13 > 0:24:16What makes Caledonian crows so special
0:24:16 > 0:24:19is their skill at manufacturing the right tool for the job.
0:24:22 > 0:24:24First, she removes the leafy end.
0:24:26 > 0:24:30She holds it on her left side, a matter of personal choice.
0:24:38 > 0:24:39She makes it look so easy.
0:24:42 > 0:24:44Time for the juvenile to have a go.
0:24:53 > 0:24:54But it doesn't quite reach.
0:25:03 > 0:25:05This should do the trick.
0:25:09 > 0:25:12But he's got to get the grub to bite,
0:25:12 > 0:25:13and that's not so easy.
0:25:19 > 0:25:21It's tantalisingly close.
0:25:33 > 0:25:36The stick is a bit too long,
0:25:36 > 0:25:38so he decides to shorten it.
0:25:38 > 0:25:39It's now spot-on.
0:25:44 > 0:25:46His newly-acquired skills pay off.
0:25:50 > 0:25:53Spy Crow tests how difficult it really is.
0:26:03 > 0:26:05Now, that's what's called beginner's luck!
0:26:09 > 0:26:12Crows are certainly smart, but when it comes to using tools,
0:26:12 > 0:26:15our nearest animal relatives are king.
0:26:18 > 0:26:20In Senegal, the chimps' favourite snacks
0:26:20 > 0:26:22are found in these huge termite mounds.
0:26:22 > 0:26:25And they, too, use sticks to catch them.
0:26:27 > 0:26:31The chimps fish out termites by getting them to bite the sticks.
0:26:35 > 0:26:38Youngsters learn to make these simple tools by watching the adults.
0:26:46 > 0:26:47But stealing from Mum is easier.
0:26:51 > 0:26:54Better still, he's been given one to practise with.
0:26:58 > 0:27:01Even at this age, they start adapting what they have...
0:27:02 > 0:27:05..then graduate to selecting and modifying their own sticks.
0:27:09 > 0:27:11There's quite an art to using them.
0:27:11 > 0:27:15It takes a good four to five years to perfect the technique.
0:27:19 > 0:27:21Termites have a painful bite,
0:27:21 > 0:27:23so they need to be careful.
0:27:34 > 0:27:37The chimps' mastery of sticks doesn't end here.
0:27:41 > 0:27:43This is Spy Bushbaby.
0:27:44 > 0:27:46He's based on an animal they naturally hunt.
0:27:52 > 0:27:54Hiding in his protective log,
0:27:54 > 0:27:56he's arousing great curiosity.
0:28:04 > 0:28:06All seems calm,
0:28:06 > 0:28:09but this young male is reaching maturity.
0:28:10 > 0:28:13So when a female arrives, he's desperate to impress.
0:28:13 > 0:28:15CHIMP SHRIEKS
0:28:20 > 0:28:24And this bushbaby is bigger than normal.
0:28:24 > 0:28:26So it could be the male's chance to make an impression.
0:28:27 > 0:28:29He checks she's watching,
0:28:29 > 0:28:31and begins his performance.
0:28:31 > 0:28:33CHIMP SHRIEKS
0:28:37 > 0:28:39For her eyes only,
0:28:39 > 0:28:41an ostentatious show of bravado.
0:28:43 > 0:28:46A classic case of showing off.
0:28:48 > 0:28:50He checks she's still looking...
0:28:55 > 0:28:56..then ups the ante.
0:29:04 > 0:29:06Branches make a flamboyant weapon.
0:29:16 > 0:29:18But she's seen straight through him.
0:29:23 > 0:29:25It's all a bit embarrassing.
0:29:30 > 0:29:33Trying to impress a female by taking on Spy Bushbaby
0:29:33 > 0:29:35was somewhat ill-advised.
0:29:38 > 0:29:41Females are the experts at hunting real bushbabies.
0:29:43 > 0:29:45They use a well-crafted weapon -
0:29:45 > 0:29:46a spear.
0:29:47 > 0:29:50During the day, when their prey hide in hollow trees,
0:29:50 > 0:29:53the chimps use sharpened sticks to catch them.
0:29:55 > 0:29:58The best hunters continually modify their weapon
0:29:58 > 0:30:01to suit the shape and depth of the hole.
0:30:07 > 0:30:10The male has a less refined technique.
0:30:10 > 0:30:12His spear isn't even straight.
0:30:22 > 0:30:26It's a huge contrast with the considered expertise of the female.
0:30:34 > 0:30:36The male favours brute force.
0:30:44 > 0:30:47When the stick breaks, he even tries to scare it out.
0:30:50 > 0:30:53Fortunately, the youngsters generally learn from their mother.
0:30:57 > 0:30:59But the male perseveres.
0:30:59 > 0:31:02And this time, he's made a bit more effort with his spear.
0:31:05 > 0:31:07It's just a shame he didn't make it shorter.
0:31:14 > 0:31:16There's little for a young one to learn here.
0:31:23 > 0:31:26For the youngsters, just making a stick is an achievement.
0:31:33 > 0:31:36Making one long and strong enough is even harder.
0:31:41 > 0:31:44It's both technically complicated and hugely frustrating.
0:31:51 > 0:31:54Even for the experts, there are no guarantees of success.
0:32:00 > 0:32:02The bushbaby squeezes out,
0:32:02 > 0:32:04and in a flash, it's gone.
0:32:04 > 0:32:06CHIMP SHRIEKS
0:32:09 > 0:32:13But there is one bushbaby that might just be easier to catch.
0:32:16 > 0:32:18This female comes prepared...
0:32:24 > 0:32:27..but uses a thicker branch to test the reaction.
0:32:34 > 0:32:36She fashions a better weapon...
0:32:42 > 0:32:45..but then has second thoughts.
0:32:45 > 0:32:46She tickles it instead.
0:32:52 > 0:32:55Spy Bushbaby lives to spy another day.
0:33:02 > 0:33:05Intelligence allows animals to solve complex problems.
0:33:07 > 0:33:09The inhabitants of the Amazon rainforest
0:33:09 > 0:33:11have their own wealth of specialist knowledge.
0:33:12 > 0:33:15This is Spy Sloth.
0:33:15 > 0:33:19He's here to reveal how the animals find and use jungle remedies.
0:33:23 > 0:33:2725% of our medicines were discovered in the rainforest,
0:33:27 > 0:33:30but its animal inhabitants know of many more.
0:33:33 > 0:33:36He soon attracts the interest of a real three-toed sloth.
0:33:45 > 0:33:50Their first encounter is a very slow affair.
0:34:03 > 0:34:07Spy Sloth's close-up view reveals something remarkable.
0:34:10 > 0:34:13Its fur is crawling with other life.
0:34:15 > 0:34:19Up to 900 moths and beetles can live on a single sloth.
0:34:22 > 0:34:24They aerate his fur and prevent infections.
0:34:29 > 0:34:31As well as the insects,
0:34:31 > 0:34:3484 different fungi also thrive here.
0:34:34 > 0:34:37Many are antibiotic or antimalarial,
0:34:37 > 0:34:40and some have been shown to destroy cancer cells.
0:34:44 > 0:34:47Usually, there is only one sloth per tree,
0:34:47 > 0:34:50so this requires some careful negotiation.
0:35:01 > 0:35:02It's not just the sloth's fur
0:35:02 > 0:35:05that harbours a medical treasure trove.
0:35:05 > 0:35:07So, it seems, does the tree it eats.
0:35:10 > 0:35:14Cecropia is renowned by indigenous people for its curative properties.
0:35:16 > 0:35:18It's used to ward off aches and pains,
0:35:18 > 0:35:19treat asthma,
0:35:19 > 0:35:22and is even an effective diabetes treatment.
0:35:31 > 0:35:33But sloths aren't the only animals
0:35:33 > 0:35:36who have discovered the rainforest's medicinal secrets.
0:35:41 > 0:35:45Macaws are one of the most intelligent birds in the world,
0:35:45 > 0:35:48and they, too, have extensive knowledge of jungle remedies.
0:35:53 > 0:35:57They gather on these muddy cliffs for a very particular reason.
0:35:59 > 0:36:02To find out why, Spy Macaw joins the flock.
0:36:15 > 0:36:18Cavities mined in the cliffs reveal the reason for its attraction.
0:36:19 > 0:36:21They eat clay,
0:36:21 > 0:36:24a special kind, with therapeutic qualities.
0:36:29 > 0:36:30When food is scarce,
0:36:30 > 0:36:35macaws are forced to eat fruit and seeds containing natural poisons.
0:36:35 > 0:36:37This clay provides the antidote.
0:36:39 > 0:36:42It helps neutralise the toxins in their stomachs
0:36:42 > 0:36:44and prevents them being absorbed.
0:36:46 > 0:36:48In the muddy clay pools below,
0:36:48 > 0:36:52other jungle inhabitants are also seeking remedies of their own.
0:36:54 > 0:36:56These are white-lipped peccaries.
0:36:58 > 0:37:01They, too, come for the health-giving mud.
0:37:01 > 0:37:05Spy Peccary has a poolside view of all the comings and goings.
0:37:07 > 0:37:10Like macaws, peccaries also need help with their digestion.
0:37:14 > 0:37:18And there are other valuable ingredients in this special mud -
0:37:18 > 0:37:21mineral supplements they can't get elsewhere.
0:37:31 > 0:37:33Trips to this rainforest pharmacy
0:37:33 > 0:37:36are a vital part of the peccaries' lives.
0:37:38 > 0:37:41Spy Peccary's presence helps reassure the nervous visitors
0:37:41 > 0:37:44that this clay lick is safe and predator-free.
0:37:47 > 0:37:50Like macaws, dusky-billed parrotlets
0:37:50 > 0:37:53use clay to combat toxins in their diet,
0:37:53 > 0:37:55and gain mineral supplements in the process.
0:37:59 > 0:38:00For male butterflies,
0:38:00 > 0:38:03the salts they sip from the mud are needed for breeding.
0:38:05 > 0:38:09When they mate, they pass these vital minerals to the females.
0:38:11 > 0:38:13As the crowds build,
0:38:13 > 0:38:16the most secretive creature of them all pays a visit.
0:38:20 > 0:38:24A tapir - a distant relative of horses and rhinos.
0:38:30 > 0:38:33He needs the clay to kill harmful bacteria
0:38:33 > 0:38:35and balance the acids in his stomach.
0:38:44 > 0:38:45Reassured by the gathering,
0:38:45 > 0:38:47yet more skittish creatures arrive.
0:38:50 > 0:38:51Black spider monkeys.
0:38:56 > 0:38:59Spy Monkey is also filming and, like Spy Peccary,
0:38:59 > 0:39:01his presence reassures the troop
0:39:01 > 0:39:03that that there are no predators around.
0:39:06 > 0:39:10The monkeys' diet of fruit lacks essential minerals,
0:39:10 > 0:39:13including magnesium, iron, calcium and phosphorus.
0:39:15 > 0:39:18But here, they get all the supplements they need.
0:39:23 > 0:39:26The knowledge of the health-giving properties of the clay
0:39:26 > 0:39:29is passed down the generations from mother to baby.
0:39:33 > 0:39:36It's a magical scene, with so many different creatures
0:39:36 > 0:39:39taking advantage of the healing power of this miraculous mud.
0:39:51 > 0:39:52Perhaps one day,
0:39:52 > 0:39:55rainforest medicines will lead us to more human cures.
0:39:58 > 0:39:59Having taken their treatment,
0:39:59 > 0:40:02the macaws return to the jungle and its boundless riches.
0:40:10 > 0:40:12In North America,
0:40:12 > 0:40:14the forest's bounty is much more fleeting.
0:40:16 > 0:40:17So, for grey squirrels,
0:40:17 > 0:40:20surviving the winter needs both brain power
0:40:20 > 0:40:22and maybe even a criminal mind.
0:40:27 > 0:40:31Each autumn, a squirrel buries around 10,000 nuts.
0:40:31 > 0:40:33Its memory is so phenomenal,
0:40:33 > 0:40:35it can retrieve up to 4,000 of them.
0:40:38 > 0:40:40To achieve this feat, as winter approaches,
0:40:40 > 0:40:45the area of the brain responsible for memory enlarges 15%.
0:40:47 > 0:40:50The squirrels show another brainy trait - cunning.
0:40:53 > 0:40:55A Spy Squirrel, bearing gifts,
0:40:55 > 0:40:57is ready to record their devious behaviour.
0:41:04 > 0:41:06He looks a soft touch.
0:41:08 > 0:41:09But the squirrel needs to be sure.
0:41:11 > 0:41:13He lashes his tail to show confidence.
0:41:16 > 0:41:18Fluffing it up makes him appear bigger,
0:41:18 > 0:41:19and shows who's boss.
0:41:32 > 0:41:34Spy Squirrel is a pushover.
0:41:34 > 0:41:36He's going to be popular.
0:41:40 > 0:41:42The nut is immediately stashed away.
0:41:44 > 0:41:47But clever minds can also be devious...
0:41:50 > 0:41:52..and this squirrel watches where the nut is hidden.
0:41:55 > 0:41:58As soon as it's buried, she makes her move.
0:42:05 > 0:42:07OK if you don't get caught...
0:42:07 > 0:42:09but there's big trouble if you do.
0:42:38 > 0:42:41The duped squirrel needs to be craftier this time.
0:42:47 > 0:42:49The crook may still be watching,
0:42:49 > 0:42:51but this is what he wants.
0:42:52 > 0:42:55In a shameless display of overacting,
0:42:55 > 0:42:57he pretends to bury his nut.
0:43:06 > 0:43:09The thief waits until the performance is over...
0:43:13 > 0:43:15..then quietly sneaks in.
0:43:18 > 0:43:20But there's no nut to pilfer here.
0:43:20 > 0:43:22Hardly surprising.
0:43:22 > 0:43:25It's stashed in his intended victim's mouth.
0:43:30 > 0:43:32With the nut raider preoccupied,
0:43:32 > 0:43:34he can either eat it, or bury it secretly.
0:43:37 > 0:43:40But the thief hasn't abandoned her life of crime.
0:43:42 > 0:43:44Spy Squirrel has a new nut,
0:43:44 > 0:43:46one with a camera.
0:43:57 > 0:43:59Theft is such an easy option,
0:43:59 > 0:44:01around a fifth of all squirrels steal nuts,
0:44:01 > 0:44:03rather than forage for them.
0:44:08 > 0:44:11It's a crafty way of letting others do the hard work.
0:44:22 > 0:44:25But this time, the thief has picked the wrong nut.
0:44:37 > 0:44:40When the snow finally arrives,
0:44:40 > 0:44:43the squirrel's phenomenal memory map comes into its own.
0:44:54 > 0:44:55Their hidden stores
0:44:55 > 0:44:59keep these crafty little creatures alive until spring.
0:45:05 > 0:45:07In a cold, harsh winter,
0:45:07 > 0:45:09deception can be a life-saver.
0:45:13 > 0:45:15On the sun-drenched African savanna,
0:45:15 > 0:45:18subterfuge is just as important,
0:45:18 > 0:45:19but for a very different reason.
0:45:21 > 0:45:24Here, a male ostrich and his mate
0:45:24 > 0:45:27will raise the offspring of up to five of his other females.
0:45:37 > 0:45:39They put all their eggs in one basket,
0:45:39 > 0:45:41creating one huge nest.
0:45:45 > 0:45:48Joining them is Spy Ostrich Chick.
0:45:55 > 0:45:58For the male, it's just another member of his ever-expanding brood.
0:46:08 > 0:46:10Spy Chick is in the perfect spot,
0:46:10 > 0:46:13as new life hatches all around.
0:46:26 > 0:46:29This spy creature receives the same devotion and protection
0:46:29 > 0:46:30as the real chicks.
0:46:42 > 0:46:44With a large brood to look after,
0:46:44 > 0:46:46ostriches are always alert for danger.
0:46:47 > 0:46:48A leopard.
0:47:01 > 0:47:03All the young can do
0:47:03 > 0:47:04is stick close to their father.
0:47:12 > 0:47:14But the female is a master of deception.
0:47:17 > 0:47:19When there's nowhere to hide,
0:47:19 > 0:47:22making yourself conspicuous is the next-best option.
0:47:32 > 0:47:37She launches a carefully planned and ostentatious display,
0:47:37 > 0:47:40one designed to catch the leopard's attention,
0:47:40 > 0:47:43luring him away from where the babies are hiding.
0:47:48 > 0:47:50She pretends she's injured and helpless,
0:47:50 > 0:47:52so tantalising for a predator.
0:47:54 > 0:47:56The leopard can't resist following.
0:48:11 > 0:48:14But he eventually realises he's been had.
0:48:14 > 0:48:16There will be no easy meal today.
0:48:21 > 0:48:23With the leopard lured away,
0:48:23 > 0:48:24the parents can relax.
0:48:33 > 0:48:36As much as you can, with 20 young in tow.
0:48:46 > 0:48:49But perhaps the cleverest scam in the animal world
0:48:49 > 0:48:52can be found in South Africa's Kalahari Desert.
0:48:57 > 0:49:01At the heart of this deception is the drongo,
0:49:01 > 0:49:04a bird that likes to hang out with meerkats.
0:49:07 > 0:49:10To delve deeper into the crafty world of the drongo,
0:49:10 > 0:49:12a new spy camera is needed.
0:49:15 > 0:49:19Spy Termite Mound is a natural part of the landscape -
0:49:19 > 0:49:24except it can move, and, of course, it has a camera.
0:49:29 > 0:49:32The meerkats feel at home with this new arrival,
0:49:32 > 0:49:34and continue to forage for insects.
0:49:37 > 0:49:39While they eat, a meerkat is on sentry duty,
0:49:39 > 0:49:41looking for danger.
0:49:44 > 0:49:47Spy Termite Mound gives a little bit of extra height.
0:49:48 > 0:49:52Drongos have keen eyesight, and as they can perch higher,
0:49:52 > 0:49:54they often spot the danger first.
0:49:55 > 0:49:57Martial eagles are a serious threat.
0:49:59 > 0:50:00DRONGO CHIRPS
0:50:00 > 0:50:02The drongo's alarm alerts the meerkats.
0:50:03 > 0:50:04MEERKAT BARKS
0:50:06 > 0:50:08They, in turn, call and run for cover.
0:50:19 > 0:50:21Having their own lookout bird
0:50:21 > 0:50:23helps the meerkats spend more time feeding.
0:50:29 > 0:50:30But there is a price to pay.
0:50:35 > 0:50:38The drongo isn't quite as selfless as he seems,
0:50:38 > 0:50:41and has learned to turn this alarm to his advantage.
0:50:43 > 0:50:46He becomes an expert on their habits,
0:50:46 > 0:50:49learning that when an adult finds food,
0:50:49 > 0:50:51it calls out to the youngsters to share.
0:50:54 > 0:50:57As the food is about to be exchanged,
0:50:57 > 0:50:59the drongo calls the alarm...
0:50:59 > 0:51:01DRONGO CHIRPS
0:51:01 > 0:51:03..but this time, it's a trick.
0:51:03 > 0:51:06As the meerkats abandon their food and flee,
0:51:06 > 0:51:08the drongo steals their meal.
0:51:20 > 0:51:21Onto a good thing,
0:51:21 > 0:51:24the drongo tries again.
0:51:24 > 0:51:25DRONGO CHIRPS
0:51:27 > 0:51:29But the meerkats know when they've been duped.
0:51:34 > 0:51:37And this time, no-one reacts at all.
0:51:39 > 0:51:41So the drongo takes it to the next level.
0:51:41 > 0:51:43DRONGO CHIRPING INTENSIFIES
0:51:44 > 0:51:47But even screaming the alarm in their face doesn't work.
0:51:51 > 0:51:55The meerkats are smart enough to know a cheat when they hear one.
0:51:55 > 0:51:56Or are they?
0:51:56 > 0:51:58The drongo has another trick to pull.
0:51:58 > 0:52:00DRONGO BARKS
0:52:00 > 0:52:03This time, the drongo mimics the meerkats' own alarm call.
0:52:08 > 0:52:11It's so accurate, the meerkats are duped again.
0:52:19 > 0:52:22Drongos get over a fifth of their daily meals
0:52:22 > 0:52:24by making false alarms and stealing.
0:52:30 > 0:52:32When he's exhausted all his tricks,
0:52:32 > 0:52:34he tries a more brazen approach.
0:52:44 > 0:52:46But he's pushed his luck too far.
0:52:46 > 0:52:49He must try his scams elsewhere.
0:52:53 > 0:52:57The intelligence of animals is sometimes so extraordinary,
0:52:57 > 0:52:58it can truly amaze.
0:53:04 > 0:53:08In Borneo, the orang-utans have ventured back to the human world
0:53:08 > 0:53:10and are bathing in the river.
0:53:14 > 0:53:17One of the spy cameras is soon spotted...
0:53:24 > 0:53:27..inadvertently filming an intimate moment
0:53:27 > 0:53:29when the pair enjoy the cooling water.
0:53:53 > 0:53:57The images captured show an animal with extraordinary mental capacity,
0:53:57 > 0:54:01one that contemplates and considers in a way we recognise.
0:54:15 > 0:54:17Then, something happens
0:54:17 > 0:54:20that confirms just how similar their way of thinking is to our own.
0:54:23 > 0:54:26At a jungle hut, this female finds a saw.
0:54:33 > 0:54:35Despite being totally wild,
0:54:35 > 0:54:37somehow she has worked out what to do with it.
0:54:42 > 0:54:45Like us, orang-utans have an opposable thumb
0:54:45 > 0:54:48that allows them to grasp and handle objects with precision.
0:54:51 > 0:54:55Over 20 years ago, a rescue orang-utan learned how to saw
0:54:55 > 0:54:57by watching people constructing the huts here.
0:54:59 > 0:55:02But this is a totally different and wild orang-utan.
0:55:04 > 0:55:06She seems to take pride in her work...
0:55:08 > 0:55:09..even clearing away the sawdust.
0:55:19 > 0:55:23She's so smart, she uses her feet as a vice to steady the branch.
0:55:27 > 0:55:30Filming a wild-born and free-living orang-utan
0:55:30 > 0:55:33mastering this complex task is remarkable.
0:55:38 > 0:55:41But now, she's not the only orang-utan sawing.
0:55:45 > 0:55:47Spy Orang-utan has joined her.
0:55:55 > 0:55:58It seems to be bringing out a competitive streak.
0:55:58 > 0:56:00She's becoming even more enthusiastic.
0:56:18 > 0:56:22But, for a novice, sawing is tiring work.
0:56:23 > 0:56:25She's lost all momentum.
0:56:31 > 0:56:34Then, finally, calls it a day.
0:56:34 > 0:56:37Spy Orang-utan may have machine-like stamina,
0:56:37 > 0:56:40but it's the astonishing and versatile mind
0:56:40 > 0:56:43of the real orang-utan that's won the day.
0:56:43 > 0:56:44She's certainly earned her rest.
0:56:50 > 0:56:54In the animal world, intelligence shows itself in ways that, once,
0:56:54 > 0:56:56we would never have thought possible.
0:56:56 > 0:56:58From the cleverness of using tools...
0:57:00 > 0:57:01..to the craftiness of deception.
0:57:03 > 0:57:05From problem-solving...
0:57:06 > 0:57:07..to making weapons...
0:57:09 > 0:57:11..or finding jungle cures...
0:57:12 > 0:57:14..we're only just starting
0:57:14 > 0:57:17to realise how clever animals really are.
0:57:20 > 0:57:24Next time, the spy creatures look at extraordinary animal friendships
0:57:24 > 0:57:27to see how similar many of them are to our own.