Nature

This may be the closest we come to meeting an alien on Earth -- the octopus.

They couldn't be more different from us.

But is a connection possible?

SCHEEL: You look at them, and you feel like they're looking back.

That's not an illusion.

They are looking back.

After years of studying octopuses in the wild, one man was driven to find out.

SCHEEL: I am going to fill my living room with a large tank of salt water.

He'll bring an octopus into his home... SCHEEL: It's coming.

It's coming.

Alright.

There we go!

...and introduce her to the family.

LAUREL: Her arm is now up my sleeve.

Meet Heidi.

LAUREL: Heidi, you're being -- you're being naughty.

You know, she comes over to the wall of the tank and just kind of like all excited to see you.

Every encounter turns what we know about these alien creatures on its head.

SCHEEL: We take our way of existence for granted, but there are other ways of being.

The octopuses followed a different evolutionary path, making them different from all the other intelligent animals on this planet.

But me?

I'm less intrigued by the differences and more interested in our similarities and the nature of a relationship I might have with such a creature.

This year, I got to experiment with an idea.

What would I find out if I invited an octopus... into my home?

What kind of a connection is possible with an animal that has three hearts and blue blood running through its veins?

My name is David Scheel.

I'm professor of marine biology at Alaska Pacific University, here in Anchorage.

I've studied all sorts of animals, but for the last 25 years, my focus has been on... octopuses.

I have two girls.

Juniper is away at university right now, and Laurel is with me about half the time -- lives here.

Laurel is 16.

She's in 10th grade.

We should check with her, make sure Dad hasn't screwed that up.

Hey, Laurel.

LAUREL: Yeah?

You're 16 right?

In 10th grade?

LAUREL: Yep.

SCHEEL: There we go.

[ Chuckles ] I'm going out on a limb a little, taking my octopus fascination one step further.

I'm going to fill my living room with a large tank of salt water.

My daughter's in and out of the house, but she was eager to have a pet, and so this is a compromise between a girl who really wanted a dog and a dad who's overly interested in octopuses.

Actually it's not a compromise.

[ Laughs ] I got the octopus.

Yeah, we have the lamp... LAUREL: Lit.

SCHEEL: Yeah, so it's lit and, um... Inviting an octopus into your home, is no small undertaking.

Here we go.

It's coming.

It's coming.

Alright.

There we go.

This new setup is gonna allow me to spend more time with an octopus than I have been able to do otherwise.

Here in Alaska, I work with the species that's native to these cold waters -- the giant Pacific octopus.

But I wanted something that was different, something that will be new to me -- a warmer-water species that's faster and more active.

This is a species that's been kept in aquariums to be studied for its intelligence.

It's an octopus cyanea, known as the day octopus.

They call it that because, unlike some other octopus species, these guys are active during the day, and so you get to see them more.

Yep, pulling hard.

Well, just a minute I'll put you in the tank.

No, no, not yet, not yet.

Just a minute.

There you go.

There you go.

There she goes.

Ooh, nice color change.

Oh, look at this.

Nice.

I mean, I guess the big thing for me about keeping an animal in the home is it's just more relaxed.

If I don't want to do anything, I don't have to do anything.

I can just see what the animal does.

And I'm not trying to do science here.

I'm just trying to think a little bit, so it's just a chance to be more available and more present for whatever the animal is living day to day.

She's very careful to keep her eyeball in view of mine.

And she's already checking me out.

I always get the sense when I'm scuba diving that they play this game with you.

Octopuses adapt their environments around them to their own liking.

They clean out a hole, under a rock or in a crevice, blowing out sand and debris with their siphon.

And at that point, it is not just shelter -- it's home.

[ Sniffles ] Hey, there.

Are you interested in some food?

Octopus love crab.

Oh, there it is.

She's definitely feeling for it.

Oh, oh, oh, she's after the tube not the crab.

There we go.

There we go.

There we go.

Oh.

Alright, look at the color pattern.

That is a satisfied octopus.

I like the texture she's put on.

She didn't have that before.

The papillae coming up around the eye and the sort of bumps and things all over her head.

It's very nice.

Now she at least will know that the tube and the environment have interesting possibilities.

Laurel is also going to be helping me take care of the octopus.

You know, the octopus was very happy to see Laurel every day.

LAUREL: Hello.

SCHEEL: Laurel was just glad to have a pet that was glad to see her.

Yeah.

I think a lot of her pets were kind of indifferent to her -- her goldfish and her rabbit outside.

So an octopus is kinda fun 'cause it comes running.

LAUREL: It looks like she's coming back over.

SCHEEL: Laurel would send me little video clips of the octopus getting up and waiting on the glass and ready to play.

And I -- You know, I'm sure Laurel looked forward to it every day.

LAUREL: Want to come here, Heidi?

Some of the things that she would do reminded me of what, like, dogs would do.

Oh!

You're already up here.

Come here!

You know, she comes over to the wall of the tank and just kind of like all excited to see you.

And so, being an intelligent animal means you need a lot of stimulus, so being played with or having just, like, interactions with people is entertaining for her.

SCHEEL: Laurel, at times, she'd sit for 30 minutes with the octopus just holding onto her and wait for it to let go.

LAUREL: Now she took something.

[ Chuckles ] SCHEEL: So she'd sit there with her hand in the aquarium for 30 minutes.

So, they're pretty affectionate.

LAUREL: She's filming more of the sand right now.

Well, now she's filming me.

[ Laughs ] Hi, Heidi!

The reason we call her Heidi was 'cause when we first got her, she spent a very, very long time in her den, and she was just hiding the whole time.

And she didn't seem to want to come out.

And then basically once we taught her that we meant food, she just grabbed on and was like, "Okay, I'm keeping you with me."

SCHEEL: The cephalopod community -- we're all excited about octopuses and we're a fairly close-knit group of researchers -- share all kinds of different experiences and advice.

Well, hi, there!

GRASSE: Hi, David, how you doing?

SCHEEL: Alright, how are you?

Bret is an expert on the early stages of cephalopod life -- that group of animals that includes octopuses, cuttlefish, and squid.

GRASSE: So how's everything going over there?

'Cause I've never kept an octopus in my living room before.

[ Chuckles ] SCHEEL: You want to take a look at the setup?

GRASSE: Yeah, I'd love to!

SCHEEL: Alright.

Let's see if I can get the computer over there and show you.

So she's actually out right now.

GRASSE: Oh, yeah.

Yeah, yeah.

That's great.

She's got good marbled coloration going on there.

SCHEEL: My day octopus is already a few months old.

But at Bret's lab, we can get a glimpse into the first few weeks of a cephalopod's life.

GRASSE: We're, you know, watching the mother until she starts going through her egg-laying phase.

And once she starts laying her eggs, she'll sit there and pulse jets of water over her eggs.

And what that does is basically keep them oxygenated, and the eggs continue to develop until they get to basically look almost like little octopuses inside of each individual egg.

And then we know they can kind of hatch at any time.

SCHEEL: This is one of the few places you can see octopuses hatch from the egg.

From this moment, octopuses are on their own.

The first instinct of this hatchling is to construct a den out of whatever it can find.

Baby bobtail squid hide by sticking grains of sand to their bodies with a mucus extruded from their skin.

These are all hardwired little predators.

They don't hesitate to take down prey, even when it's two or three times their size.

Their color-changing cells start flashing while they're still in the egg.

Three types of cells with neural control make color change almost instantaneous.

These young pyjama squid use this to produce their signature striped pattern.

But there is one cephalopod that is the master.

Just a few centimeters long, these baby flamboyant cuttles can beguile anyone with a shape-shift, that is out of this world.

The day octopus can also perform an extraordinary display with their skin.

And I already have some experience with these octopus in the wild.

I've been in the water with them on the southwest coast of Madagascar, working with the local Vezo fishermen, designing a way to census the octopus population.

Reece has an amazing ability to find the octopus in amongst the coral.

REECE: You see there, the head?

SCHEEL: Oh, yeah.

Yeah.

REECE: You see?

SCHEEL: Yeah.

It's amazing to me how fast they are here.

The octopuses in Alaska -- they're kind of big, slow giants, and these guys are just quick and agile and limber, and they're -- Really, everything they do, they seem to do it at ramped-up speed.

I've had them in my hands, and then they're already gone.

And then I look over, and Reece has caught it again.

[ Chuckles ] REECE: [ Indistinct ] SCHEEL: The day octopus is a master of camouflage.

Its skin can change color in milliseconds.

And it can use muscles on the surface of its skin... to change texture, as well.

And this species has recently been recorded demonstrating an incredible behavior with its color displays.

It's a display called "passing cloud."

It's just so stunningly beautiful.

It's like, "Wow, what's that?"

The thing about passing cloud is it's a very impressive physiological ability.

And at the same time, it's a bit of a mystery.

The most common theory you hear is that octopuses are using passing cloud to startle its prey and trap it in the web of its arms.

My octopus is showing impressive color changes of her own.

Observing what we're doing.

We've seen how closely the octopus we have here at the house is watching our eyes.

You look at them, and you feel like they're looking back.

That's not an illusion.

They are looking back.

And so, when you have an animal that's that attentive to another animal's eyes, that is very suggestive of high level of awareness of the world.

Well, scientists do find questions about octopus intelligence particularly intriguing.

At the Seattle Aquarium, they did some experiments, giving different objects to octopuses, and recorded what happened.

In one of the most telling experiments, the researchers put a pill bottle in the tank with just enough air in it to float.

There was no food or anything to be gained here, but still, a few octopuses found reason to be interested.

Nothing happened at first, but after the fourth time, the octopus would -- would bounce -- take the pill bottle, and blow it out into a stream of water that was circulating around the tank -- there it goes... ...and the water would bring the pill bottle back to the octopus again, and it would start the whole thing over again.

It would do it again and again -- blowing the pill bottle into the water until it came back, and then blowing it back into the water again.

A bit like bouncing a ball.

The conclusion from this experiment was simple.

It fit all the criteria for play.

Play, of course, is something that intelligent animals do.

And Laurel spends many hours playing with Heidi.

LAUREL: [ Chuckles ] Now, now she's -- Now you say hello to me.

SCHEEL: Octopuses have up to 240 suckers on their arms.

Each has sensitive chemical receptors.

Heidi can touch and taste Laurel at the same time.

LAUREL: She just lightly jetted at me.

She doesn't want me to leave.

SCHEEL: Octopus also have estrogen, like humans do.

Is it possible that Heidi can be detecting the estrogen on Laurel's skin?

Does Heidi maybe taste the difference between males and females?

LAUREL: Heidi!

[ Laughs ] Her arm is now up my sleeve.

That's fun.

Heidi, you're being -- you're being naughty.

She's lifting herself almost all the way out of the tank right now.

Come here.

Come here.

Come here.

Oh!

Now I'm wet.

[ Chuckles ] SCHEEL: The idea of Laurel having any kind of relationship with a mollusk is extraordinary when you think about it.

This is an animal that has 600 million years of distance from us.

That's almost as deep as any divide can be between two animals.

With three hearts, no bones, a beak with a venomous bite, and a gut that runs through its brain, to one point of view, the octopus is completely alien.

As science-fiction movies have long demonstrated, humans spend a lot of imagination dreaming up what it might be like to meet an alien.

In the latest blockbuster, "Arrival," the filmmakers imagine what it might be like to encounter a species that changes the way we think about the universe.

And I think it's an important observation that they culminate this encounter with cephalopod-like figures from outer space.

To really understand quite how alien octopuses are to us and to every other intelligent form of life on Earth, we need to appreciate the unique evolutionary path of the octopus on the tree of life.

It's Octopus Lecture 101 for my students.

Okay, what does the tree of life look like?

Here are a couple of artistic versions.

They're just to give you a quick overview.

Here's the plants.

Here's the animals.

This is the branch that has the... To meet the common ancestor, of humans and octopus, you would have to travel back in time more than half a billion years -- millions of years before any animal crawled out of the ocean onto the land.

So here's the octopus, and here's the human, and their last common ancestor is something that was fairly like a flatworm.

And what would this common ancestor look like?

Well, maybe a little bit like this -- a small, flat worm.

Barely any eyes to speak of with a cluster of neurons forming just a pinprick of a brain.

From this beginning, one path of evolution gave rise to every bird and every reptile, every mammal, all of them, us included, all adaptations from this common ancestor -- designs of eyes and brains and hearts becoming ever more sophisticated and more varied.

That was the path for every intelligent animal, except for one.

That is why people talk about meeting an octopus being like meeting an alien, because... octopus branch of life evolved on its own separate track, inventing its own version of an eye, its own version of a brain, its own version of a heart.

The octopus is a unique expression of evolution, so any contact I have with these animals is possible because evolution built our eyes, our minds, our behavior twice over.

There is no other intelligent animal on the planet that has evolved separately from all the other animals, in this way.

And this is why people are so fascinated to make contact and to understand every facet of this very particular sentience.

In aquarium tanks all around the world, octopuses have been put through their paces.

They have solved complex mazes, even learned symbols, passed memory tests for their rewards.

Learning from feedback.

Forward thinking.

Applying diverse behaviors to novel situations.

When you stack them one on top of another, that's what we call intelligence.

And the unique evolutionary journey of the octopus... Come on, Heidi.

...makes this intelligence particularly intriguing.

For a start, the intelligence of an octopus is not just gathered as one lump in its head, like it is with us.

Parts of the octopus intelligence are distributed in its arms.

And that means that, to some extent, the body can be its own controller rather than having a body being driven entirely around by the brain.

Eight arms independently gathering data and reacting to the world around them.

All kinds of intelligence require feedback.

I think that's why humans are intelligent, is 'cause we just, you know, know you try and you learn from your errors.

So, trial and error is really the intelligent thing.

And octopuses make trial and error do more than you might expect.

Our understanding of octopus intelligence took another leap forward when, in Indonesia, in 2009, researchers reported a veined octopus doing something truly remarkable.

It was a discovery that would put our understanding of the octopus onto a new level of sentience, occupied by only a few species of animals.

Living on the sandflats, they have very few places to hide.

But this octopus has a unique solution to the problem.

It carries half a coconut shell with it.

But it needs to find something else to complete the set.

Two coconut halves -- a perfect shelter.

What is remarkable about this discovery is how the octopus dismantles its home... ...carries it around... ...uses it to hide and to ambush prey.

And now it's putting it back together again.

This octopus is thinking ahead.

This is real flexibility.

The octopus has to anticipate to carry that awkward object around and then correctly assemble the separate parts to create a single functioning tool.

And less than 1% of all animals have ever been seen to use tools.

And it's not just science that is starting to take notice of the extraordinary octopus.

Laurel is showing me all the attention these animals are getting from people.

LAUREL: I've seen Heidi do this before.

SCHEEL: Oh, yeah.

So, my real question on this one is who's taking the video?

Is it another octopus who's stolen a GoPro?

LAUREL: [ Laughs ] Maybe he's filming himself.

Yeah, he's doing a vlog.

SCHEEL: Oh, yeah, a video blog!

LAUREL: [ Laughs ] Yeah.

And he's like, "Look at this strange thing that came and found me."

[ Laughs ] SCHEEL: We're no longer just eating octopuses.

People are meeting them now, making contact in the ocean.

WOMAN: I held the fish in front of his shell and he grabbed it from my hand.

He touched my finger with his arm, and I think that we were both a bit surprised, so we both pulled back.

This time, he grabbed my finger and he tried to pull my finger inside... SCHEEL: This clip has 11 million hits!

WOMAN: He was punching the fish away with his arms.

It was the funniest thing I've ever seen -- this octopus trying to punch away little fish.

LAUREL: [ Laughs ] WOMAN: It was definitely the coolest encounter I've had with an octopus.

I tried to see how he responds to different objects, like a conch shell or a mirror, but he never really responds the way that I expect.

I went on holiday, and I didn't see him a few days before, and I was worried he wouldn't be there anymore when I came back.

But I found him.

He swam up to me, and he touched my foot.

SCHEEL: "985 clams disliked this video."

[ Laughs ] LAUREL: [ Laughs ] That's funny.

SCHEEL: This specific one.

LAUREL: Yep.

SCHEEL: This one also went viral.

It wasn't hard to get Heidi to demonstrate these impressive skills of contortion.

She doesn't have a skeleton.

You want to go through?

Come on, Heidi.

Come out and play.

Come on.

Octopus are able to squeeze through the smallest of gaps.

Attagirl.

That's it.

Come on, sweetie.

Good girl.

Come on.

Come on.

A little squeeze.

There we go.

That a girl.

Keep coming.

You can do it.

Almost.

You can squeeze.

I need to be very careful.

This ability makes Heidi a real escape risk.

She is quite capable of leaving the tank if she gets a chance.

In fact, octopus can move across land with surprising ease.

[ Seagulls squawking ] In Northern Australia, it's part of the hunting strategy of the Abdopus octopus.

Octopus have gills, so they can't survive out here for long.

But they do absorb some oxygen through their skin... ...allowing them enough time to find a new rock pool with new opportunities.

And leaving the water is not just being seen in the wild.

There's stories everywhere.

There's far more stories than there are data.

One story tells of a trawler in the English Channel and an octopus caught in a net and left on deck.

Somehow, it manages to slither from the deck, down the companionway, into the cabin, and hours later is found hiding in a teapot.

NEWS REPORTER: Now we turn to a tale of escape - a daring act by an octopus.

Inky the octopus... SCHEEL: In a New Zealand aquarium, another octopus, named Inky, becomes famous on the news when it was reported for escaping its tank and crawling across the floor, disappearing down a drain, escaping to the sea.

NEWS REPORTER: The manager of the Aquarium says Inky will not be pursued.

SCHEEL: Some of my favorite stories are about pet octopus popping out of their tank to snack on their neighbors.

My investigations into this suggest an octopus leaving its tank to grab a snack does happen.

But finding its way back?

That is probably urban legend.

[ Dog barking ] [ Birds chirping ] Back in our living room, Heidi has become a fully-fledged, consummate predator.

Sometimes, when Heidi hunts, before the attack, she might be camouflaged.

But as she gets ready, she'll drop all her camouflage... ...and then there's this ghostly white form... ...and then pounce.

While she's a master of her environment... MAN: ...invigorated by daily sunshine... SCHEEL: ...she is also taking part in our lives outside the tank, adapting to our daily routine with remarkable ease.

LAUREL: We'd come in, we'd turn on the TV, we'd sit down, and a couple of minutes later, she'd move over to the front of the tank, closer to the TV.

She started doing that pretty much every time we would come into the living room to watch TV.

And so, we'd have TV time with the octopus.

I think this is how she would orient herself if she's actually watching it, 'cause her eyes just moved so that they're more facing towards the TV.

MAN: An oceanic wanderer stops by to be cleaned... LAUREL: There seems to be, like, very subtle changes, like slight widening of eyes and, like, a slightly faster breathing.

MAN: ...invigorated by daily sunshine, marine life flourishes... SCHEEL: But is Heidi really watching TV with Laurel?

The idea isn't as far-fetched as it sounds.

Researchers, for a long time, have used video to show cuttlefish and octopuses and see how they react to it.

Are they signaling to one another?

Is there sort of a language of behavior?

So it's completely believable that Heidi is watching television.

MAN: ...long distances along the reef in order to get here.

SCHEEL: But to what extent is she watching us?

Increasingly, we can see just how well Heidi recognizes us.

There is good evidence that she is aware of who we are.

So sometimes, I take extra measures to be someone else.

This isn't an octopus horror show.

It's actually based on hard science.

There is plenty of evidence that shows octopus recognize people.

I'm gonna weigh Heidi today, and to do that, I've got to capture her so that I can lift her up on the scale.

And she might not like that, so I'm gonna wear a mask.

Well, you see, there's an interesting study that was done in 2008 that showed that octopuses in aquariums remember and recognize individual human faces.

The experiment dressed two people in identical uniforms.

One would feed the octopus... ...the other would annoy the octopus with a bristly stick.

Within just a week, the octopus would move towards the person that fed them, and avoid -- or even squirt -- the annoying one.

What do you think, Heidi?

Here goes.

And so, when I weigh Heidi, this just might make it a little easier for her to forgive me for capturing her and weighing her.

It's harder to tell in a living-room experience, but Laurel's quite convinced that Heidi showed a difference between the way she reacted to either of us and visitors to the house.

Recognizing people on the other side of the glass is an unlikely ability for a creature that comes from the ocean.

Okay.

You've been weighed.

And there is a new dimension being added to this study of octopus intelligence -- personality.

Scientists have used the relationships between octopus and humans in an aquarium setting like this... LAUREL: Whoop, that's the first time that she's ever taken it away from me.

SCHEEL: ...to demonstrate how individual octopus have their own personality.

And Laurel is certainly convinced about the particular character of our octopus.

LAUREL: Heidi's definitely a trouble maker.

When we feed her, she grabs onto you.

Heidi!

And then she jets at you.

Wet!

Oh, that was very wet.

It's just cold.

She got it right up my sleeve.

You know, you're trying to pull away with this octopus stuck to your arm and she's jetting water in your face and it's -- you know, she's trying to get attention and she doesn't want us to leave the room.

SCHEEL: There have now been several studies that have looked for signs of personality in different cephalopods and typically find that there are individual personalities.

Bringing the octopus into an area of study normally reserved for animals like chimpanzees and dolphins is another milestone in the understanding of octopus intelligence and certainly the first time for an invertebrate.

This experience with the octopus in our living room helps me understand a little more about how they experience the world, but it also highlights a paradox -- one of the cephalopod mysteries.

Scientists have a model that suggests that some of the things that go along with intelligence are longer life-spans and complex social lives.

Neither of those things apply to octopuses.

They live short lives, and they spend them alone.

The fact that octopuses are solitary seems at odds with how Heidi can have this kind of intelligent relationship with us at all.

Recently, I've been investigating a unique discovery in Australia... Attagirl.

...one that suggests octopuses may not always be solitary after all.

This extraordinary discovery happened in 2009 in a small bay not that far from Sydney Harbor.

A diver named Matt Lawrence plunged over the side of his boat.

And drifting along, just exploring in areas of the bay that everyone else found were pretty boring.

And in the middle of a silty area, he came across something very unexpected... ...piles of empty scallop shells.

And in amongst the scallop shells, about a dozen octopuses had made their homes.

We have nicknamed the site "Octopolis," although it's hardly a city of octopuses.

But an aggregation like this is unheard of anywhere else in the world.

I'm helping to try and find out what's going on here.

And working with Matt, we are putting some remote cameras down to get a closer look at the behavior at this unusual site.

We want to capture the, sort of, natural behavior, and Matt started putting GoPro down -- you know, one or two GoPros on the site to sort of film the octopuses when divers weren't around.

And so, it's kind of exciting to come back and track what's going on with the octopuses from moment to moment.

LAWRENCE: So that's the octopus... SCHEEL: Yeah, it's pulling down another camera... LAWRENCE: ...taking over the camera now, the main one.

Ah, he's got the camera.

No wonder we can't keep the cameras alive.

SCHEEL: They take a beating.

LAWRENCE: I love it when this happens and then another video records the octopus vandalizing our cameras.

SCHEEL: [ Laughs ] And when the cameras aren't getting pulled apart, they are recording social interactions that you simply can't see anywhere else.

They appear to signal to one another.

They make themselves look really dark and conspicuous and large when they're approaching, and rather flat and pale when they're retreating.

You see octopuses reaching towards each other.

I wouldn't want to speculate yet what that is, but they're interacting.

This is pretty new.

So this is more of that signaling, but why does the approaching octopus evict this one and not that one?

I wonder if it's possible that they're, like, recognizing one another.

You know... LAWRENCE: Yeah.

SCHEEL: ...that they prefer one animal over another.

You know, like a smaller rival male... LAWRENCE: It's the high five.

SCHEEL: Oh, yeah, there it is.

LAWRENCE: Go over and touch each other and just -- yeah.

SCHEEL: Octopolis is sort of a wonderland.

It's just kind of awe-inspiring.

There's octopuses side by side in adjacent dens, and that's so surprising for an animal that we always thought was solitary.

You see octopuses approaching one another and chasing one another.

We see them wrestle with one another, which is always fairly spectacular 'cause it's like watching two umbrellas have a fight.

[ Laughs ] What makes Octopolis unique is that this is a spot where the conditions occur that force social skills upon the octopus.

It's a very exciting find.

It does sort of shake up the cephalopod world a little bit to think that octopuses may have to deal with one another and, in doing so, sort of hone their social skills.

The research has only just begun, and we'll need to work out how these environmental conditions might create what we thought did not happen... ...octopuses living side by side with one another.

Each new discovery makes a little more sense of how Heidi can have a relationship like she does with Laurel and me.

Having an octopus in our living room has enabled us an intimacy not possible in the lab.

And last night, I witnessed something I've never seen recorded before.

You know, if she is dreaming, this is a dramatic moment.

You could almost just narrate the body changes and narrate the dream.

So, here she's asleep, she sees a crab, and her color starts to change a little bit.

Then she turns all dark.

Octopuses will do that when they leave the bottom.

This is a camouflage, like she's just subdued a crab and now she's going to sit there and eat it and she doesn't want anyone to notice her.

It's a very unusual behavior to see the color come and go on her mantel like that.

I mean, just to be able to see all the different color patterns just flashing, one after another.

You don't usually see that when an animal is sleeping.

This really is fascinating.

But, yeah, if she's dreaming, that's the dream.

[ Laughs ] The solitary octopus does not fit our theories of how animal intelligence can evolve, and yet it is.

And there is another thing about the octopus which also contradicts our theories on the development of intelligence.

It is something Laurel and I will soon have to come to terms with because most octopus live for only a year or two at most.

It is incredible that octopus can become so sophisticated in such a short time.

There is a connection here that crosses a divide not just from air into water, but also across half a billion years of separation.

And it's been a privilege to have a relationship with such a strange and wonderful creature.

To learn more about what you've seen on this "Nature" program, visit pbs.org.