All language subtitles for Wild Assassins 08

From tropical rainforests,

across farmland and city streets...

to Africa's vast grasslands,

these creatures carry one
of the deadliest weapons on Earth.

Capable of bringing human
civilisation to a halt.

Silent and unseen...

but deadly.

One of nature's
evolutionary weapons...

...disease.

Welcome to the world
of wild assassins.

Zoonotic diseases have
impacted human civilization

throughout history...

transmitted from countless
animals across the globe,

to humans.

From the first ever plague
that spread across the globe,

killing 25 million people.

To the Black Death

that eradicated 60 percent of
the population of Europe.

These plagues have torn
through civilisations...

leaving societies,

governments, and farming practices
changed forever.

Outbreaks of diseases
have changed humanity...

overturning the world
as we know it.

From bats, rats, and monkeys,

to ticks and mosquitoes,

to dogs and countless livestock...

unaware of the weapon they bear,

these animals have the power
to collapse societies,

spreading new and old diseases

that can be fatal.

Ancient, hidden, and mighty.

One of nature's deadliest weapons.

On Earth for 34 million years,

found on every continent
populated by man,

there are as many of them
as there are humans,

carriers of countless diseases.

Rats.

Blamed for outbreaks
throughout history,

man and the wild rat have
constantly been enemies.

Found anywhere
from the world's inner cities

to its surrounding meadows
and grasslands,

they boast a population
of 7 billion.

Drawn to human homes
for food and shelter...

these unwelcome house guests
can wreak havoc.

Chewing through wires,
destroying furniture.

They can cause permanent damage.

Rats will eat anything
they can get their paws on.

The great city of New York
is overrun with these pests,

with an estimated two million
calling this city home.

Intelligent creatures,
they avoid traps and evade danger.

It takes a team of professionals
to tackle a rat infestation.

Their existence has created
countless issues for the city

that never sleeps.

The biggest threat rats pose
to humans, however, is disease.

Rats carry pathogens that
can transmit diseases to humans.

In the Middle Ages,

rats carried the bacteria
that caused the Black Death.

Their fleas transmitting the plague
to humans.

In modern society,

humans have gone on to experiment
and test on rats...

revealing them
to be highly intelligent creatures,

frequently outperforming humans
in cognitive tests.

Mankind's fear of rats is rooted
in a history of disease,

but there is much humans
have learned from them.

The lab rat has made
invaluable contributions

to many medical advancements.

But sadly at the cost of abuse.

As humans and rats
come closer together,

the chances of spreading
disease have increased.

Despite mankind's history
of conflict with rats...

these rodents do play an important
role in every ecosystem.

They maintain the health
of grasslands and forests

while also providing a major
food source for many predators.

Despite hosting many diseases
and parasites...

rats are essential to our planet.

Without them,
ecosystems would collapse.

Scavengers of our cities.

Found in almost every household
across the globe,

man's best friend...

yet countless carry
a deadly disease.

Dogs.

Dogs were the first animals
domesticated by humans.

In the present day,

more than 471 million dogs
are kept as pets worldwide.

Found in thousands of households
across the globe...

dogs are loyal, lovable,
and caring creatures.

Who throughout history
have been respected

for their obedience
and devotion to man.

Dogs have always been protectors,

living alongside
and within human homes peacefully.

They are a constant
source of happiness for children

and adults alike.

Providing comfort and companionship
for many people across the globe.

In most countries, it is required
by law to vaccinate

both cats and dogs against rabies.

It is a disease that is 100 percent
preventable with vaccination...

yet in up to 99 percent of cases,
domestic dogs are responsible

for rabies virus transmission
to humans.

Symptoms of rabies
in dogs include fever,

difficulty swallowing,
excessive drooling,

staggering, seizures,
and even paralysis,

with stray dogs being more likely
to carry the disease.

If a human is bitten
by a rabid dog,

the effects can be fatal.

While dogs are not
the most rabid creatures,

their close contact with humans

makes them the most likely
to transfer it to them.

Dogs may be man's best friend,

but vaccines are important
in stopping the spread of disease...

ensuring we can live
alongside these animals

for centuries to come.

Man's best friend.

Found on every continent on Earth,
in woodlands and meadows...

with over 900 species...

these minute arachnids...

can bite and burrow into human skin,

spreading disease from within.

Ticks.

Often mistakenly thought
to be insects,

ticks are actually classed
as arachnids.

Armed with six to eight legs,
and curved teeth.

They use both to climb onto
and attach themselves to a host.

As parasites, they feed
on the blood of their victim.

In America alone, 50,000 people
are bitten by a tick annually.

Most active in the spring
and summer,

ticks cannot fly or jump,

only crawl.

They can carry infections
such as Lyme disease

and tick-borne encephalitis...

transmitting these diseases
in under 48 hours.

If bitten,

prompt removal...

is crucial.

Found in tropical rainforests
across the globe,

curious and carefree creatures,

their bite and scratch can
spread deadly diseases.

Monkeys.

Monkeys have been on Earth
for 85 million years.

Found on five
of the Earth's continents,

they are classified
in two main groups:

Old world monkeys
and new world monkeys.

Between them, there are
over 200 different species.

Old world monkeys include baboons,

red colobuses, and macaques.

While new world monkeys are made up

of five primate families
found across South America,

such as marmosets, tamarinds,

capuchins, and spider monkeys.

Agile and intelligent primates,

monkeys are some of the closest
animal relatives to humans.

We all have evolved
from a common ancestor

over the last 60 million years,

but we are not entirely similar.

Monkeys walk on all fours,

have a tail, and smaller brains
than humans.

But that does not mean
they lack in intelligence,

as studies show monkeys
have good cognitive skills.

Monkeys can spread diseases
to humans.

Every year,
people are bitten or scratched.

Some countries have banned monkeys
as pets because of this...

but the risk of infection
still remains.

Risks from monkey bites
include serious wound infections,

Herpes B virus and rabies.

They may be
extraordinary creatures...

but as human expansion grows,

mankind is brought closer
to these animals,

the chances of contracting
deadly diseases, increasing.

Oh, my gosh!

Monkeys have been tested
on for decades.

Tens of thousands are used
in research and testing

around the world every year,

mainly to check
the safety and effectiveness

of human medicines and vaccines.

Research relating to human
reproduction and brain functions.

Several countries have
banned testing on apes...

but experimenting
on monkeys continues,

despite the fact they experience
emotion in similar ways to humans.

They can feel pain,

psychological distress,
and suffering.

Monkeys' resemblance
to humans has cost them.

Countless monkeys across
the globe are tested on,

primarily for human medicines
and vaccines.

Emotionally intelligent creatures...

monkeys can feel suffering.

Innumerable organisations
across the globe

are fighting to stop
the use of monkeys in labs,

contesting for more
humane alternatives.

Monkeys play in important role
in their native habitats,

pollinating flowers
and dispersing seeds...

a keystone species.

They deserve to be safeguarded.

Found on every continent
populated by man.

Feeding on human blood.

These flying insects
carry deadly diseases,

half of the human population
is at risk.

Mosquitoes.

On Earth for over
220 million years,

flying insects found in almost
every part of the world.

Across the globe, there were
over 3,000 species of mosquito,

estimate to have population
of 110 trillion.

They have the power
to transmit many diseases,

from chikungunya, dengue,

West Nile virus,

yellow fever,

Zika viruses and malaria.

Feeding on human blood...

they easily transmit disease,

many of which can be deadly.

Infected mosquitoes transmit
viruses through their saliva.

Small and unassuming,

most will not feel their bite
until it is too late.

They wield a deadly weapon.

Despite the deadly
diseases they carry,

mosquitoes are essential
to planet Earth.

Not only are they pollinators,

but mosquitoes and their larvae
are essential food sources

for many creatures,

including birds, bats,
and aquatic animals.

Without mosquitoes many populations
would be impacted.

While they can spread diseases,

mosquitoes must feed
from warm-blooded creatures

in order for them to survive.

Three point six billion livestock
animals inhabit Earth,

sources of meat, dairy,
and materials.

From the 940 million cattle
reared as livestock,

to half the global pig population
living in China.

To the 40 billion chickens raised
in factory farms, across the globe.

These creatures can
spread deadly diseases.

Livestock.

Integral to every continent
populated by men,

these creatures provided meat, milk,
labour, and leather.

Harbourers of the first animal
pathogen identified as a virus,

cattle.

Cows have been reared as cattle
for over 10,000 years.

Today there is an estimated
1.5 billion on Earth.

Every continent except Antarctica
raises at least one breed of cattle.

They are providers of meat,

milk, labour,

and hundreds of other products
that people use in everyday life.

Yet, despite all their uses,

cattle carry countless
deadly diseases,

from anthrax to E. coli,
to bovine tuberculosis.

Another disease they carry
is foot and mouth disease,

a highly contagious disease

that was first identified
in the 16th century.

Bovine tuberculosis first
became a serious problem

in Victorian England.

As people crowded together
in large cities.

Many of the cows they were
sourcing milk from were infected.

In the present day,

milk is still the common source
of infection.

Other diseases cattle carry
are transmitted the same way...

or by contact
with infected animals.

In modern day,

it is much less likely
to contract these diseases,

with laws in place to limit
the chances of infection.

But the risk of disease

still remains a threat
to cattle themselves,

the biggest killer of cattle today.

In cramped conditions,
deadly diseases spread quicker.

Cattle deserve to roam free.

Found and raised
all over the world,

with a population of 784 million,

lovers of the outdoors,
they are found in sties.

Responsible for many pandemics
and epidemics.

Pigs.

Pigs are farmed and raised
all over the world.

First domesticated 9000 years ago,

they now boast a population
of 780 million.

Pigs are gentle creatures
with surprising intelligence,

preferring to live in stable
families or small groups.

As humans have spread
across the globe,

pigs have followed alongside.

Most pigs in the world
today are farmed,

raised for slaughter.

Many live in cramped conditions...

where disease can thrive.

Pigs can spread diseases to humans,

such as salmonella, hepatitis,
pathogenic E. coli,

and swine influenza.

Between 2009 and 2010,
swine flu spread across the globe.

Pigs are vulnerable to diseases

that affect not only humans

but can wipe out entire
pig populations.

Welfare is
of the utmost importance.

To protect these creatures
and prevent the spread...

of deadly diseases.

In farms, fields, and factories
across the globe

lives the most populous bird
in the world.

With a population
of over 33 billion,

they live in close quarters...

spreading and harbouring diseases.

Chickens.

Chickens have been on Earth
since before the Common Era...

aiding human civilisations across
the globe for thousands of years.

Domestic chickens are the most
numerous bird in the world.

Recently revealed to be intelligent
and emotional beings,

they are social
and gregarious birds,

thriving in the company
of other hens,

with one cockerel
to every five to 15.

They build strong bonds
and connections with one another.

But when kept on their own,

chickens are known to become anxious
and depressed.

Chickens experience
social contagion,

or what we know as empathy,

meaning they feel distressed

when they see other
chickens in distress.

They are emotionally
complex creatures.

The most populous bird
in the world,

chickens are also the most abused.

Though they can barely fly,

the chicken has become
the world's most migratory bird...

in food form.

Living in intensely
constricted conditions,

chickens can spread disease.

From salmonella and campylobacter,

to Newcastle disease
and avian influenza.

Pandemic experts say another
avian flu pandemic will come.

It is not a question of if,
but when.

This is a disease exacerbated
by factory farming.

Livestock animals have been central
to human survival for millennia,

first as food, tools, and leather
for ancient hunter-gatherers.

The livestock reared by farmers
for meat, milk, and labour.

Without them, human civilisation

wouldn't have been unable
to progress,

yet many of these creatures
are treated inhumanely.

In close confinement,
they're vulnerable to diseases

that can wipe out
entire populations.

On farms, they're exposed
to unclean water, harmful chemicals

and dead animals,
all of which can spread disease.

Despite the countless assets
they offer to humanity,

they are not treated with dignity,
respect, or compassion.

Efforts to stop the mistreatment
of livestock animals

are the only way to limit
the spread of disease

and improve animal welfare.

To keep all creatures
on Earth safe...

protecting livestock is key.

On Earth for many millennia,

these creatures have become immune
to the diseases they carry.

They can wreak havoc
on human populations.

With over 1400 species
across the globe.

Bats.

Found almost everywhere
in the world,

bats have been on Earth
for 50 million years.

Some bats are solitary,

but many live in colonies
in their thousands...

helping to increase
reproductive success.

With billions of bats
across the globe,

they are the second largest group
of mammals by species.

Bats have evolved over the millennia
to reach speeds of over 160 kph.

Navigate using echo location,

and have a highly adaptive
immune system.

The largest bats
in the world are fruit bats.

They play an essential role
in pollination and seed dispersal,

feasting on fruit,
berries, leaves, and bark.

Not all bats are herbivores,

with many eating insects,
beetles, gnats, and crickets.

They are evolutionary wonders,
able to hunt food in the darkness,

consume 1200 mosquitoes
in a single hour,

and they have an unparalleled
immune system.

Bats are the source
of more dangerous viruses

than any other mammal,

able to transfer diseases
to humans with their bite,

or from a human consuming
an infected animal.

Bats themselves are unaffected
by the diseases they carry,

their immune systems having evolved
to fight off infections quickly.

Bats are long-term hosts for Ebola,
rabies, the Marburg virus

and potentially even coronavirus...

all of which can be deadly,
if contracted by a human.

Evolutionary tricks and fierce
immune systems have made bats

the perfect hosts
for these diseases.

The diseases from bats
becoming deadlier

as their strong immune systems
battle against them.

Making the consequences
even more alarming

when these diseases
are transmitted.

Ecological systems across
the globe are changing,

leading to more opportunities
for viruses like these to emerge.

With coronavirus bringing the world
to a standstill in recent years.

Ebola causing major loss
of life throughout Africa.

And outbreaks of the Marburg virus
on the rise.

As mankind expands,

so does the risk of contracting...

deadly diseases.

Evolution has made bats
the perfect hosts for disease.

Their powerful immune systems
producing deadly pathogens.

As humans and animals
come closer together,

the consequences can be alarming,

yet bats are not to blame.

It was humans who altered
the ecological systems worldwide.

Bats themselves could be the cure,

their immune systems
the perfect study

for how humans can tackle
these diseases.

Bats play an important role
in Earth's ecosystems,

as pollinators and controlling
pest species.

Bats all across the world...

deserve to be protected.

All creatures on planet Earth
carry diseases...

including humans.

But not all can be deadly.

Across the globe,

diseases are spreading further
and faster than ever before.

As human civilisation expands,

mankind and nature are
brought closer together,

creating the perfect opportunities
for diseases to spread.

From the food and drink we consume,

to the creatures in our homes...

disease is everywhere,

but many can be avoided.

Introducing safer
farming practises.

Battling against climate change.

And further humane research
into vaccinations and medicines

could protect humans and animals
alike from even more diseases.

There is so much to learn
from the animals

that carry these deadly diseases.

From how to cure them...

treat them and prevent the spread.

To pave a brighter path
for the future

will take the efforts...

of all mankind.

Subtitle Caption by ZestCorp