They're our planet's first builders,
nature's architects and engineers,
crafting homes of spectacular design
in every corner of the globe.
Some are elegantly simple, others surprisingly complex.
So it looks like a teenager's bedroom from the outside,
but if you were to cut this
right down the middle and look inside...
Whether they were made by beaks or paws,
these homes have a universal purpose --
to keep their owners safe
from a dangerous world
as they give birth and raise a family.
It makes it a perfect bear home.
It's secure, it's dry.
And it turns out that the quest for real estate in the wild
is all about the same three things we value most --
location, location, location.
A strategic location in space...
At a precise location in time...
These are the essential must-haves
of just the right home.
It looks like an ideal place to live, doesn't it?
The valley of the Snake River --
Jackson Hole, Wyoming.
t features beautiful Rocky Mountain views,
plenty of running water,
and a good mix of trees and shrubbery.
It's the perfect spot to build your dream house
and to commune with nature.
The surprising thing is,
much of what you see here isn't exactly natural.
It was shaped and crafted by a rodent --
the beaver.
This is where a family of beavers is making its home.
The dad has been homesteading here for nearly a decade,
and he and his mate have a couple of kits.
Their ancestors have been
working this area for thousands of years.
For this family, like all homeowners,
location is crucial.
For once they chose this spot, they set about
giving it a complete makeover
to meet their exacting specifications.
I'm Chris Morgan.
I'm an ecologist and I'm fascinated by
how animals construct their homes
and why they decide to live where they do.
There he is.
There's our inhabitant.
Beavers are very choosy about where they build.
There's one thing no beaver can do without.
It's top of the list in their real-estate requirements,
and that's a stream.
When beavers hear the sound of running water,
they feel compelled to build.
But before they start work on their house,
they first build a dam.
And check out this dam.
It's amazing! It's huge!
Beavers are the only mammals besides humans
that construct dams
to block water.
[Laugh]
And they build big ones.
A beaver dam can be hundreds of feet long,
and it's strong enough to support me.
It is such an impressive construction.
I mean, look at this. It's packed with
big logs down to these tiny twigs,
and every single of of them -- look --
has been chewed off by a beaver.
These are all different building materials,
and one of the most impressive to me is the fact that
these beavers will swim with and push and hoist
these giants rocks -- look at the size of that --
right onto the top of the dam.
And they use these big rocks as anchors,
along with the giant logs,
and then they intersperse it with mud and grass
and other debris -- look at that, perfect --
and create this watertight system
with one idea in mind, and that is to
bring the water level up behind this dam.
And the difference between
this water level and that water level
is approaching, I'd guess, three feet.
It's quite something.
These beavers are not only designers and architects,
but stonemasons, woodworkers, builders.
They do it all.
The dam converts a stream into a pond.
Wow.
That's just the place to live if you're a water-loving,
web-footed beaver
who's much better at swimming than walking.
Now that the pond's nice and deep,
the beaver family instinctively shift gears
to start working on their house -- the lodge.
With all this construction work, they need a lot of wood.
Fortunately, their ancestors evolved into lumberjacks,
and they work the night shift.
Since the tender
inner bark of trees is a beaver's favorite food,
they can harvest a crop while they gather lumber.
Watch out!
But there is a limit to how much they can drag,
so our clever beavers let the water do the work.
When you think about it, it's really not a stretch
to call these guys hydro-engineers.
So they'll excavate these channels.
Look at this. They've actually dug the mud
out of this with their front paws.
They'll float these big logs out,
back to where the dam is and where the lodge is,
and it allows them as an aquatic mammal
to swim up these channels and access the new trees.
What an awesome system.
By damming the stream so it floods its banks
and then digging a network of canals,
the beavers have devised a way to swim right into the forest
to reach more trees.
It's a watery world.
And through their efforts,
they've also reshaped the entire neighborhood,
transforming a woodland into a wetland.
Of course, beavers don't work from a blueprint,
but they certainly seem to have one in mind.
And since this pair has built dams and lodges before,
their instincts are bolstered by experience.
This is the heart of it all,
the heart of the beaver neighborhood.
Look at the size of this.
This is the lodge.
My goodness.
It looks like a total jumbled mess of logs,
kind of like a volcano of logs.
They've stripped off the bark and eaten the inner bark.
Look at those teeth marks.
And then they use their food, the food waste,
as building material, so it looks like
a teenager's bedroom from the outside,
but if you were to cut this right down the middle
and look inside...
You'd see just how complex it is.
This lodge is build up against the pond's shore,
but the entrances are underwater for security.
Above is a suite of rooms.
Amazingly, the beavers actually carve them from the inside,
chewing and clawing their way through
that solid mound of wood and earth.
There's a kind of a mud room, where they can dry off,
and a family room, where they eat and sleep.
They left the domed roof a little loose
to vent out CO2 and to let in fresh air.
And as a finishing touch, they'll excavate the mud
on the shore side to create a moat
so their home will be completely surrounded by water.
Beaver lodges are all built around the same general lines,
but each one is unique,
a designer home that's perfectly matched to its surroundings.
The goal is to have a house that's cozy and warm,
safe and secure, where they can raise
their young ones -- in fact, the same things
that motivate every house-building animal.
But finding just the right location to build in,
that's the challenge.
Most animals can't do what beavers do.
They can't alter their neighborhood
to meet their needs.
So they have to make the best use of their habitat,
taking advantage of whatever nature offers.
This red-faced warbler has found a convenient spot
to raise her family --
right on the ground,
tucked away under a fallen branch.
The warbler's neighbor, a brown creeper,
takes an entirely different approach.
It climbs straight up a tree trunk
to hide its nest inside the bark.
And these house finches
make their home among the spines of a cholla cactus.
That's like putting up a barbed-wire fence
to keep out trespassers.
Of course,
the conditions where you live help determine
where you put your home.
A great desert skink escapes the searing heat
of the Australian Outback
by digging a network of underground tunnels.
Down here, it can be nearly 40 degrees cooler
than up on the surface.
A gopher tortoise makes its home underground too
because the pine forest it lives in is prone to fire.
No matter where you make your home,
your surroundings are bound to present
both challenges and opportunities.
A good homemaker knows how to deal with both.
The salt marsh sparrow makes its nest,
not surprisingly,
in coastal salt marshes from Maine to Virginia.
A house near the shore offers a lot of attractions,
but it also harbors risks.
This is a place where ocean and land collide,
a place of constant change and powerful forces.
As a home site, it has its drawbacks.
You see, the female sparrow
builds her nest on the ground,
and the marsh floods with the tide.
Twice each day, the pull of the moon
draws the sea into the marsh.
And twice each month, when the moon is full,
and again when it's new, the tides are especially high.
Nesting here is certainly risky.
But on the other hand, there's less competition
for space and food, so this is where the sparrow
has carved out a niche.
She's in a race against time and the rising tide.
The sparrow weaves her nest under the top layer of grass
so it's hidden from predators
but high enough so it should stay above water.
It takes 24 to 26 days
from the time she begins laying her eggs
until her last chicks fledge --
almost the exact length of the lunar cycle.
There's no margin for error.
For most of the sparrow nests,
flooding is inevitable.
It can be a disaster.
A female sparrow has no way to get her eggs
back into the nest if they float away.
That's why the nest is constructed with
an overhanging dome to make sure the eggs stay put.
As long as they remain within the confines of the nest,
they can bob around for an hour or two until the tide recedes.
When mom returns, she'll warm them up,
and they'll continue to incubate.
After the eggs hatch, the chicks have
no protective shell to float around in,
so they're more vulnerable than ever.
Young chicks can't swim.
They're defenseless against the rising water.
But once they're about five days old,
they're strong enough to climb up above
a flooded nest and wait out the tide.
This chick has made it through the night.
She was just big enough to reach safety.
Her siblings weren't so lucky.
A few inches can make all the difference
between a successful nest and a catastrophic failure.
But enough sparrows survive
to keep the little birds coming back to these marshes
year after year.
One creature that lives on the water
but avoids the problems of a flooded nest
is the hooded merganser.
Mergansers are striking little ducks,
especially the males,
with their black-and-white crests.
In the spring, they puff them up to attract a mate.
Once courtship is over,
house-hunting and child-rearing are left up to the female.
Most water fowl build their nests on the ground
or on floating mats of vegetation,
but hooded mergansers are rare ducks.
They seek out the shelter of a hollow tree.
Out of the thousands of trees in this forest,
this one is perfect.
Struck by lightning years ago, it still stands tall,
with a convenient entrance
50 feet up.
A woodpecker probably drilled out that hole
while it foraged for insects.
Over time, the hole's been widened and rubbed smooth,
perhaps by squirrels or raccoons...
And by generations of hooded merganser moms.
At the bottom of the cavity,
she lines her nest with soft down features
plucked from her own breast,
and here she lays a clutch of eggs,
up to a dozen or so.
Mergansers can afford to lay so many eggs
because they nest in a location
that's safe from the elements and from predators.
After four or five weeks,
the eggs begin to open.
Once hatching is underway,
the nest is a busy place,
and noisy.
[Chirping]
All that vocalizing promotes
a family bond, as the ducklings get used to
the sound of their mother's voice.
She won't stay in the nest for long, though.
Within hours of the last egg hatching,
the ducklings are home alone.
Their mother's not far away,
and her calls
are the only thing that could entice them
to abandon their cozy nest.
Barely a day old, they can't
fly up to the entrance, so instead,
they climb.
They're equipped with strong claws just for this purpose.
When they reach the opening, their first view
of the outside world must come as quite a shock.
It's a five-story drop.
But somewhere down below,
their mom is urging them
to leave the only home they know
so they can live the life they were born for,
and that persuades them to do something
that seems a little crazy.
Some ducklings aren't as bold as others...
And he who hesitates gets a push.
Finally,
driven by instinct and joined
to one another by an inseparable bond,
they all take the plunge.
Once they've assembled on the ground,
still following their mother's voice,
they will make their way together through the woods
to their new home on the water.
As for the tree, it won't stand empty for long.
Some other creature will take over the lease soon,
perhaps a squirrel
or a wild turkey,
and our hooded merganser will be back in residence next year
to bring another family into the world.
Few animal homes could be simpler
than the hooded merganser's.
But here in this oak forest
in the Ozark hills of southern Illinois,
you'll find homes that are almost absurdly complicated.
The builder uses whatever is at hand,
and his tower of sticks and leaves is a reflection
of the place where he lives.
The architect behind this house
is a little rodent with a good reason to build big.
He's an eastern woodrat.
He works nights,
gathering building materials
and fitting them into his grand edifice.
It's a work in progress.
As time goes on,
it'll just keep getting bigger and bigger.
Over the course of a lifetime, this woodrat's den
will grow to an enormous size,
with multiple chambers and plenty of storage space.
So why does he need such a big house?
Because the woodrat
is an avid collector, which is why he's
also known as a pack rat.
He collects food, for instance --
seeds and nuts,
fruit and leaves.
What he doesn't eat
he stores for the winter inside the den.
But woodrats are looking for more than just food.
They have a natural inclination, bordering on obsession,
to scavenge their tiny territory
for anything they find interesting
and cart it all home.
They seem especially attracted to the things we throw away --
toys,
used shotgun shells,
and anything shiny.
They just love metal.
But here's the mystery --
we have no idea why they're drawn to all this stuff.
Most of it is of no practical use to them.
It's not warm. They can't eat it.
No matter.
They're inveterate hoarders.
It all gets incorporated into the walls of the house
or socked away in a storage chamber.
All this is a far cry
from the compact
and purely functional homes of most animals,
but then, most animals lack
the woodrat's predilection for junk.
Sometimes, living in the right location
is really all about having the right kind of neighbors.
Here in the Chiricahua Mountains of southeast Arizona,
there lives a little hummingbird
that's taken that lesson to heart.
I've come to learn more about it from biologist Harold Greeney.
GREENEY: God, this is just beautiful. Wow.
He's a hummingbird expert,
and he knows how to find them by sight or by sound.
GREENEY: One strategy is to just walk fairly directly
from one spot to another and then just stop and listen.
Harold has probably found more hummingbird nests
than anyone on the planet.
GREENEY: I think she kept on going.
He has a special interest
in the hummingbird that lives around here.
It's called the black-chinned.
-She's coming in. -Is she?
GREENEY: She's gonna go.
Now she's off to the right. Here she goes.
And she just sat on the nest.
-Is she on the nest? -She just went to the nest.
Oh, no way. You spotted it.
GREENEY: Yeah. Oh, there,
she just came off the nest again.
You don't even think the nest could fit there --
Oh, that's so cool.
Wow, it's wrapped right around the branch.
You would walk right past that.
It's no bigger than a golf ball, really.
GREENEY: Yeah.
A bird so small making such a tiny, fragile home,
it's easy to see how vulnerable it can be.
And in fact, the black-chinned falls victim
to an array of predators --
squirrels, snakes, and especially other birds.
One of the worst offenders is the Mexican jay,
which makes its own nest in these woods.
Harold's good at spotting them, too.
Do you see the nest right there in the fork of that tree?
Oh, yes.
GREENEY: She's on the nest right now.
Yeah. Very nice.
I'm distracted 'cause there's one there and there's one there,
and they're both looking right down here,
seeing exactly what's going on.
GREENEY: Yeah, we're kind of close to their nest here,
and, you know, they're coming to check us out and make sure
we're not posing a threat.
They're just like any other bird, when you get down to it.
Right, right,
but they are the enemy of the hummingbird.
GREENEY: They are, in this case,
the enemy of the hummingbird.
And it's not hard to understand why.
The jays have their own young to feed,
and a hummingbird nest is so convenient.
Harold himself shot this rare view
of a jay feasting on a black-chinned's eggs.
But some hummingbird nests are safer than others,
and Harold has discovered why.
GREENEY: Not too far away here is the hawk nest.
It turns out the hummingbird
doesn't build her nest just anywhere.
Way easier to spot this one probably, eh?
GREENEY: Yes, it's slightly larger.
She often chooses a neighborhood where
she can get help from her neighbors.
Either Cooper's hawks
or their close cousins, the goshawks,
will serve the purpose.
Oh, I see.
This one's difficult to miss, that one. Wow.
GREENEY: You could probably fit
a hundred hummingbird nests inside there.
And it's sort of, you know,
at the upper level of this forest,
watching over this whole area.
Now, you'd think that a big killer like a hawk
would make short work of a hummingbird.
In fact, they don't bother with such small prey.
GREENEY: For a bird this size, the morsel is so small.
The challenge is so great.
You burn more calories chasing a hummingbird
than you get from eating it.
You know, if you had to run up this hill
to eat a Tic Tac and then go down
and come back up to get a second one...
I'd probably only do it seven or eight times.
[Laughter]
Jays, on the other hand, are perfect
meal-sized prey for hawks, who attack them from above.
The jays have only one defense --
being annoying.
When a jay finds a hawk, it sounds the alarm.
That alerts the other jays,
and they all gather round to give the hawk what for,
trying to drive it away.
And sometimes it works.
Because the hawks are such a big threat to jays,
they've become the hummingbird's protector.
As the old saying goes,
the enemy of my enemy is my friend.
Should we go up the hill and get a closer look?
GREENEY: Oh, yeah, look at this.
Spectacular.
Whoa! Beautiful.
Oh, fantastic! A great vantage point.
GREENEY: And that's the vantage point
that instills fear in the jays.
So they normally forage at all levels in the forest --
on the ground, up into the canopy --
but when they know that hawk's there,
they don't want to be underneath her because the way she hunts
is to swoop down upon them.
So from the hawk's position on high,
you can imagine a kind of cone stretching down,
taking in everything in the hawk's target area.
For the jays, it's a no-fly zone.
But for the hummingbirds, it's a safe haven,
and their nests tend to be clustered inside that zone.
The question is,
do the hummingbirds really understand what's going on here?
Do they seek out hawks when they look for a place to nest?
Well, probably not.
GREENEY: We know that the hummingbirds are
very faithful to successful nest sites,
so they build a nest, and if they are successful
in fledging a brood,
they'll come back and re-use that same site.
They may have no idea
that they're under the watchful eye of the hawks.
GREENEY: That's actually my guess, yeah.
For a black-chinned hummingbird,
the trick is finding just the right place to live
and the right neighbors to live near.
But there's more to location than being in the right place.
You also have to be there at the right time.
Winter seems like the worst possible season
for a bird to build a nest,
but the cold doesn't stop these little songbirds.
Gray jays maintain their territories all year round
in the northernmost forests of North America
and they breed
in the dead of winter.
Here in Canada's Algonquin Provincial Park,
a pair of jays is working together on their nest.
They've picked a spot
that's exposed on the south side to catch as much of
the weak winter sunlight as possible
and is nestled under a branch to offer at least
some protection against snowstorms.
It's the female's job to incubate the eggs.
She sits in the nest without a break
for nearly three frigid weeks,
doing her best to keep warm in subzero temperatures.
It's up to her mate to keep her well-fed.
There's precious little to eat in this frozen landscape,
unless you plan ahead.
During the fall, gray jays harvest
the bounty of the forest and store it away
in caches hidden in trees throughout their territory.
Bugs and berries and bits of meat
are tucked under flakes of bark.
And not just any tree will do.
Gray jays prefer black spruce for food storage.
The bark is especially flaky, and its resin seems to do
a better job of preserving perishable food.
This pair of jays spend months creating a network
of perhaps 10,000 food caches.
That meant they had to collect
and stash food hundreds of times every day
and create a mental map of their territory
to record where they put their groceries.
Their memories are phenomenal.
They manage to retrieve as much as 80% of the food they hide.
The eggs will hatch in a few weeks,
before spring has even begun.
That will give the chicks
a head start on growing up and developing brainpower.
They'll need it when fall rolls around
so they can find and store food
and remember where they put it all.
The Green Mountains of Vermont are home to
the gray jay's much larger cousin,
the common raven.
In late winter, these granite cliffs
echo with their rasping calls.
Now, while the rest of the forest
is still closed for the season,
the ravens are starting a family.
Ravens are big birds, and they build a big nest,
woven from sticks a yard long.
Because ravens are so secretive and cautious,
their nests need to be hidden out of the way,
like this one,
in a crevice on a cliff face,
with a rock overhang for protection.
It's perfect for this family.
In fact, the layout is so perfect,
it's been used for thousands of years
by countless generations of ravens.
Once the chicks hatch, they grow fast.
Within a few weeks,
they're nearly as big as their parents,
and they're ravenous.
Both adults work overtime to keep food on the table
for four hungry nestlings.
Like jays,
ravens store some food in hidden caches,
but mostly they let the winter do their hunting for them,
and winter is a cold-blooded killer.
A dead deer can feed a lot of ravens.
They're sociable birds,
happy to share a big meal with other ravens,
as well as a few neighbors.
Their calls also alert less-welcome diners.
Eagles are too big
and too powerful to disinvite.
But ravens are patient.
Once the eagle has eaten its fill,
there's still plenty left.
Some of the meat they'll eat on the spot.
But for these working parents, the main priority
is to bring food back to the nest.
Their chicks are in a hurry to grow up.
Before long, it'll be their turn to make their homes
in these ancient granite cliffs.
Many mammals do what jays and ravens do --
start a family during the winter.
But to succeed,
they need the right home in the right place.
I've been studying bears for more than 20 years.
My own work is based in the Cascade Mountains
of Washington State and up in Alaska,
but black bears are making a comeback
all over the eastern United States,
so I've come to Maryland's Allegheny Mountains
to learn more about how these bears
make their homes and where.
A bear's home is really a seasonal thing,
a hideaway where it can hibernate
during the long winter months,
and for a female, it's much more than that.
[Chuckling] Oh.
Look at that.
I love getting into the mind of a bear
and wondering what they're thinking.
So imagine a female bear in November
is looking for a place that she's going to spend
the next six months.
So she's thinking about it needs to be isolated
and insulated and safe
and maybe somewhere that's near food and water.
In the days just before she goes into her den,
she'll be drinking gallons of water
just to help her process the fat
so that she can survive the winter.
So she's got an awful lot on her mind
as she's trying to select the best home,
but this would be perfect.
This den is empty now, but last year,
for one bear, it was a very special place.
Perfect.
Completely dry and sheltered in here.
This is where it all happens.
She comes into this den alone
and she stops eating, she stops drinking.
Her heartbeats drop to about eight per minute,
her respiration, breathing, down to about eight per minute,
and she's alone.
But then something even more surprising happens.
In February, she gives birth inside this den,
half asleep, to maybe four or three cubs,
and then two months later, they follow the light
at the end of the tunnel and shadow mom as she leaves
into this big, wide world of adventure.
What a way to start life.
Black bears here in Maryland are reproducing at a rapid rate.
In some areas, their population has doubled in the past decade.
That means they often make their homes near where people live,
so the state has an interest in keeping a close eye
on the bears and locating their dens.
It's the end of March in these snowy woods.
I've met up with Harry Spiker and his team
from the Maryland Department of Natural Resources.
SPIKER: There you go.
They're checking on
the health and welfare of the local bears.
We've got a short walk in?
SPIKER: About a half-mile.
We're planning our approach to another den,
one where the residents are still at home.
She's right up there, up pretty high on the rocks.
[Whispering] They're trying to figure out
the best route to the cave,
and we have to be very quiet
because we don't want to disturb this female.
You'll hit rock wall.
Skirt around.
You can see why a bear would be drawn to this area.
We're surrounded by these giant boulders,
and there are these dark holes between them
that look perfect for denning.
And you can also see Harry's military background coming out.
He's going in first,
and if he can't dart the bear and she decides to exit,
then Georgia here is the backup.
She can hopefully dart the bear as it comes through.
[Pop]
With the bear safely tranquilized,
I can take a look inside her den.
Oh, it's a very tight space.
The perfect home, nice and secure.
Oh, wow.
Oh, four cubs.
She has four.
[Laugh]
Look at that.
There's four of them, four cubs in here,
and a big female.
She looks huge, actually, just squashed in here,
a tiny little space,
a really narrow little section of the cave,
but it makes it a perfect bear home
because it's secure, it's dry.
She's pulled in all these leaves.
Look at all these rhododendron leaves
that she's snipped from outside
and pulled in here to make a bed.
A perfect place, though.
Really healthy female and with four cubs.
That's a really good sign.
Okay, we're just pulling out the cubs
so that we can weigh them and measure them.
It's okay, little guy.
Okay, I got two here.
SPIKER: Coming out over my shoulder.
Another one there.
MAN: Yep, it's coming.
There you go, little guy.
GEORGIA: Seven on the dot, seven pounds.
Outside the den, their mom doesn't look so big.
She's only about a hundred pounds,
but she's a beauty.
She looks in really good shape.
SPIKER: Oh, she is in great shape.
Her teeth look great.
Quite a young bear, by the looks of it.
Incredible to see this this thick mat of wool under there.
-Oh, absolutely. -That's what it's all about.
She'd be lost without it.
You feeling good about her and the cubs?
SPIKER: Real good, yeah, very good.
While the team does
a full work-up on the female...
Look at that.
I get a chance to enjoy a moment
I've always dreamed off.
[Sigh]
Hey. Hey.
You guys are perfect, aren't you?
Oh, this has got to be
one of the most memorable experiences of my life.
Just look at those guys. Four of them.
And we've got two of these guys here.
As soon as you put them in your coat,
they just want to feel comfortable and warm.
They kind of chill out, and I guess it must feel like
they're close to their mom, like they are in that cave.
It's the first time
these guys have seen daylight, and I'm definitely
the first human being that they've seen.
That's an incredible thought.
It's just the biggest honor
playing surrogate mom for a few minutes.
They're lucky little bears,
with a healthy mom and a comfy den
in just the right location.
Back on the pond, winter has worked its magic,
radically transforming the beavers' world.
Their pond is nearly frozen over...
And the lodge is camouflaged under a mantle of white.
[Howling wind]
All around, the landscape may be buffeted
by 60-mile-an-hour winds
and chilled to minus-30 degrees.
Many of these animals are grazers,
so they're homeless.
They have to stay on the move, regardless of the weather,
scratching out their survival from beneath the snow.
As a result, they're exposed to the worst
that winter can dish out
and they depend upon their coats to keep out the cold.
The snow can pile up three or four feet
and everything gets a coating of ice --
everything.
For the beavers,
life couldn't be more different.
With the mud and the lodge walls frozen hard as concrete,
their home is impervious to wind and snow.
The ice on their pond may be a foot thick,
but thanks to the beavers' efforts,
the water is deep enough that it won't freeze
all the way to the bottom,
so there's plenty of room to swim.
In the lodge, winter is five months of family time,
and this family has a full house,
with two parents,
a pair of adolescents born last year,
and by late winter,
newborn kits.
With all that shared body heat, the temperature in here
may be 60 degrees warmer than outside.
The beavers' larder is near their underwater entrance,
maybe a thousand pounds of tree limbs and logs.
They can just pop out the front door,
grab a meal, and swim back in to feed.
Here in the darkness, in the safety of their lodge,
they spend most of their waking hours
reinforcing family bonds by grooming
and eating together.
For kits, like human kids,
mealtime can turn into a game.
Much of a winter's day is passed
just sleeping.
They've earned a rest.
After all, they worked hard last summer,
engineering a new habitat
and winterizing their lodge.
Now they get to enjoy all the creature comforts.
The beavers have created what every animal looks for
in a home.
Oh, wow.
It's a safe haven, a place that's warm and secure,
a place where they can give their young ones
the very best start in life.
Their nature's architects and engineers,
crafting homes of spectacular design,
and every one of these fantastic creations tells a story.
While many homeowners seek privacy,
others band together.
Competition and cooperation push and pull on village life,
giving rise to complex societies where millions of citizens
build a metropolis like nothing else on earth.
To learn more about what you've seen on this "Nature" program,
visit pbs.org.