Planet Earth is so spectacular,
it's easy to miss the smaller things in life.
But take a closer look...
and there's a whole undiscovered world.
A world where tiny heroes...
and little monsters...
need incredible superpowers...
to help them triumph against giant odds.
Life is full of hazards.
Especially for a ground squirrel only the size of a taco.
She makes her home in the cactus-covered land of America's Sonoran Desert.
A tough place to make a living.
Almost everything here is armed with claws...
spines...
or venom.
Just surviving is hard enough.
Let alone raising a family.
When spring arrives,
little desert creatures face their most challenging months.
But if they stay ahead of their enemies...
and play this prickly world to their advantage...
being tiny might just give them the edge.
Late spring.
A ground squirrel pup seeing his desert home for the first time.
For four weeks, he's been safe underground with mom...
and his six brothers and sisters.
But now he has a lot to learn about surviving in an unforgiving land.
By the end of summer, this little pup will be on his own.
Fortunately, his mom is an old hand at desert survival.
Lesson number one: get to know the neighborhood.
First impressions? Not all that welcoming.
Huge saguaros tower 12 meters high.
Just one of 300 species of cacti that grow here.
Despite their menacing appearance,
all sorts of animals rely on these prickly plants in all sorts of ways.
An elf owl,
the smallest owl in the world, nests high in the saguaro.
Protected from the sun above and predators below.
It's the perfect place to raise her new chicks.
Down in the dust, other little creatures are up early...
busy finding food before it gets too hot.
They're a ravenous bunch.
One of the residents here eats snakes for breakfast.
The roadrunner...
lives up to his name.
He can run at 30 kilometers per hour.
He needs to, to satisfy his family's growing hunger.
Three chicks in a nest protected by a spiny security fence.
Roadrunners will eat almost anything they can catch.
But he won't bite off more than he can chew.
A one-and-a-half-meter-long rattlesnake is too big.
Too dangerous.
While this venomous giant is in the neighborhood...
little animals will have to watch their backs.
Monsters patrol this desert too.
Gila monsters.
Nesting on open ground, rather than in cactus, is risky.
Gambel's quails rely on camouflage to keep their eggs safe.
But a Gila monster hunts by smell...
sampling the air with its tongue.
While there are such easy meals on the ground,
the roadrunner chicks should be safe in their cactus nursery.
A Gila monster is too big for a roadrunner to take on.
Some lizards are more bite-sized...
but harder to catch.
A zebra-tail is one of the fastest.
It also has a foolproof escape plan.
A pile of dead cactus provides a safe bolt-hole...
for lots of desert animals.
And it's more than just a hideout.
It's a home...
for a little pack rat.
She's the architect of this fortress.
An expert in construction with cacti.
Any gap in her defenses is easily patched.
These barbed wire balls are in plentiful supply.
A well-maintained pack rat den makes life very difficult for predators.
There are so many impenetrable hiding places
and fortified homes in the cactus desert,
a lone Harris's hawk struggles to catch enough prey.
But this hunter has a deadly backup plan.
The young ground squirrel must learn never to stray far from cover.
But mom has another vital lesson to teach him.
Three quarters of a cactus's weight is water.
They serve as reliable reservoirs even when rain is months away.
Pups catch on fast.
But don't always pay attention.
Diamondback rattlesnakes are ambush predators
with enough venom to kill a human.
Mom is always on high alert.
But she needs to make sure her pups are too.
And show them how to face down an enemy ten times her size.
Flagging her tail makes her pups aware of the danger...
and lets the snake know its surprise attack has been foiled.
A bold move...
but it works.
With more rattlesnakes here than anywhere else on earth,
this is one lesson the little pup cannot forget.
By early summer, temperatures are hitting 40 degrees Celsius.
Nightfall brings relief from the heat...
and new hunting opportunities.
The elf owl chicks are growing bigger and hungrier.
It's now cool enough for the pack rat to leave her fortress
and find food.
Seventy percent of her diet is cactus,
so she doesn't have to look too far.
At night, the desert crawls with all sorts of little killers.
But the most sinister looking are by no means the most deadly.
In three weeks, the owlets have quadrupled in size...
and have insatiable appetites.
Their doting parents will make 80 kills a night to keep them fed.
Until their chicks fledge in two weeks' time,
the feeding frenzy continues...
night after night.
As summer draws on,
the cacti present another gift for little desert animals.
Nocturnal blooms, brimming with nectar.
Lesser long-nosed bats are only the weight of a teaspoon,
but they fly hundreds of miles to reach this feast.
These flowers offer more nectar than almost any other.
And as the bats visit more blooms, they pollinate them along the way.
But when each flower opens, the cactus loses precious water.
So they only open once.
And for less than a day.
As different cacti bloom through spring and summer,
they provide a much-needed food source.
With mom's guidance,
the eight-week-old pup is learning when and where to find them.
Even the petals are nutritious.
Packed with the protein and carbs a growing pup needs.
These flowers may be fleeting...
but some tiny creatures have an ingenious way of preserving their riches.
Hidden deep underground...
a nest stocked with a treasured liquid.
Honeypot ants are stuffed with so much nectar,
they swell as large as a grape.
Twenty times their original size.
These living storage containers can hardly move...
and have to be cared for by the other ants.
When the outside world is barren,
this liquid gold sustains the whole colony
until better times return.
By midsummer, the temperature reaches 50 degrees Celsius.
Everyone's baking in the heat.
And the young are the most vulnerable.
Dad takes the full force of the sun to shade his chicks.
But the elf owl family can sleep comfortably.
Water evaporating from the saguaro's trunk cools the interior
and keeps their nest air-conditioned.
A thick cactus roof keeps the pack rat's home cool too.
Essential, now that it's become a nursery.
Four peanut-sized pups, blind and helpless.
They need their mother's protection.
In this heat, even cold-blooded killers seek shade.
And the pack rat's nest becomes a refuge for unwelcome guests.
Passed down from mother to daughter, these dens can be centuries old.
And extensive enough to keep nasty neighbors apart.
And anyway, it's way too hot to hunt.
In a summer this severe, the cacti shrink to two thirds their diameter.
As temperatures peak, finally change is in the air.
But this storm brings no relief.
A 100-kilometer wall of dust.
In its wake, a sign of more trouble ahead.
Each time a rattlesnake sheds its skin, it's only getting bigger.
At least the pup has learned to be more wary.
But this is not a threat.
It's an opportunity for mom to teach him another survival secret.
Chewing the skin into a paste...
and rubbing it into her fur,
makes her smell less like a squirrel and more like a snake.
As long as he keeps copying mom, the pup should be safe.
But the roadrunner's chicks will fledge soon...
and away from the nest, they'll be more exposed.
Their father must do all he can to keep their patch of desert safe.
Like a matador, he provokes his enemy.
Goading it to attack his wing feathers...
where it can do no harm.
Until finally, it's had enough.
Hopefully, it won't be back
before the roadrunner chicks can fend for themselves.
Just after summer peaks, relief finally arrives.
Monsoon storms drop ten centimeters of rain in just a few hours.
It only takes one downpour to revitalize the land.
The cacti swell, replenishing their water stores.
Enough to see this patch of desert through many months to come.
The ground squirrel pup is almost ready to go it alone.
But the Harris's hawk is back.
And this time, with reinforcements.
The cactus desert offers little creatures so much cover,
it forces Harris's hawks to hunt in packs.
Working together to flush out their victims.
These long-legged raptors are just as deadly on the ground.
Mom can only hope her pup stays put...
and doesn't panic.
He's made it.
Under his mother's guidance, he now has all the skills he needs
to turn a prickly problem into an advantage.
They may look intimidating,
but these cacti provide everything a little creature needs...
to call this place home.