Horizon (1964–…): Season 49, Episode 13 - The Secret Life of the Cat - full transcript

The thing I love about cats is that
they're very independent,

but very loving.

You can play with them.
They're comforting. They're furry.

If he's out, I get lonely.
When he's in, fine, I'm all right.

Well, you can see how lovely
it is to have him near me

and be able to stroke him.

We may love our cats,
but how much do we really know them?

They have a secret life
that remains a mystery.

With leading cat scientists,

Horizon has set up an experiment
to find out what they get up to.

..Wandering round. Go back.
Go back a bit.



Across the week,

50 cats in this village will be put
under 24-hour surveillance.

Good boy! Are you wanting to go
outside and we can see what
you're doing with that camera on?

They'll be wearing specially
designed cat cameras to show us

what they do
when they're not at home.

And carrying GPS receivers to
reveal their secret journeys.

What's unique about this
experiment is that it reveals

how 50 cats live,
crowded together...

..how they hunt and fight...

Really a classic stand-off.

..and the surprising strategies
they use to get along.

It raises the intriguing possibility
that our cats may be changing

and that could be down to us.

I'm going to find Shamley
on the map for us.



John Bradshaw and Sarah Ellis

are two of Britain's
leading cat scientists.

It should sweep round to the right.

They're on their way to the village
of Shamley Green in Surrey to

recruit cats for the study.

I think one of the things that will
be really interesting about this

study is, it's every owner's
dream to find out what their cat

does as soon as they go
through that cat flap.

Well, let's hope it's going to
be...their dreams are going to

be satisfied,
it won't be a nightmare.

The cat sniffing into the butcher's
next door and stealing sausages.
SHE LAUGHS

There are over ten million
cats in the UK

and the highest density of them
are found here,

in the southeast of England.

But despite their popularity,
scientists know surprisingly little

about their behaviour once
they've left the cat flap.

Got a fairly wide
range of types of housing

and, hopefully, types of cat here.

Yeah, definitely.

The built-up area, if I'm looking
at the map, seems to be behind us.

And then these houses in front of us
look to back all on to fields.

They want to find out more about how
far cats travel each day...

So hopefully we'll get cats roaming
out of their back gardens

and up into the farms.

..how these solitary creatures
manage to live side by side...

I'll expect some of these
houses in this more built-up area,

there might be multi-cat households.

..and where cats really
find their food.

I've really been
interested in the cat

because it's that combination of wild
animal and domestic animal,

and the changes
that are going on within it,

that I find fascinating
as a biologist.

The scientists are looking to
recruit 50 cats of all ages,

sizes and breeds.

I've got three cats,
if that's any good!

I've got one.

On average, cats live to about 15
and weigh in at around four kilos.

This is Lily. She's
an 18-month-old Bengal that I bred.

This is Obi,
short for Obi Wan Kenobi.

This is Kato.
Claude's quite a character

and he has various
girlfriends in the district.

Does quite a lot of hunting.

I want to find out where he gets
them all from. That's what I said.

They go out every night
and come back and sleep all day,

so it'll be quite
interesting to see how far they go.

My husband thinks
he just goes ten feet up the woods,

but I think he goes a lot further.

He used to belong to a lady over
the road, but he left home.

They've now got a dog.

Everyone's gathered in the village
hall to meet the scientists

and find out more
about what the study will involve.

We want to get a picture
of your cat's natural, normal life,

so don't do anything different,
don't change your routines,

don't lock the cat flap,

don't suddenly call up the local
handyman and get a cat flap put in.

Let the cat do what it usually does
and hopefully we will build up

this picture of what it's like
to be a cat in Shamley Green.

I'll now hand over to Alan,
who is the technical expert,

among many other things.

Alan Wilson's task is to devise
a new way to track the cats.

He's a world expert in tracking
wild animals.

Where we do most of that work
is in Botswana, in Africa.

So we design and build things
like this. This will fit on a lion.

LAUGHTER
This will fit on a cheetah
or an African wild dog.

The technology that Alan has
developed for the big cats is

an advanced GPS tracker.

It tracks the animal's
position, speed

and how fast they're accelerating,
step by step.

The collar has got solar
panels on the top, it's got

electronics in the top here and then
the batteries on the bottom,

and a radio antenna.

So this will give us
the position of our animals

to tens of centimetres,
300 times a second,

and how fast they're going,

so we actually get exquisitely fine
detail about what they're doing,

where they're moving,
what terrain they're moving in,

how they're hunting, when they're
successful and when they aren't.

It really is opening up whole new
measurements that weren't

possible before with traditional
tracking collars.

The information he's gathered has
transformed our understanding

about how these fearsome predators
live in the wild.

We're going to turn on the GPS
loggers.

He now has to do
the same for our pet moggies

by miniaturising his technology.

And today, he's testing it
out for the first time.

This is Zach, this is my dog.

Zach's quite an expert on testing
our collars for us.

Here's one of our wildlife collars
that we're using in Botswana.

We've developed three smaller GPS
modules we want to try on the cats.

And we can then compare
the performance of those

and see how well they work, compared
to what's our gold standard,

which is our wildlife collar.
I think it's going to be quite
challenging.

I think they're going to object to
it a lot more than our wild cats do.

And they're a lot smaller,
so the size of the collar is much
more of a challenge.

And, yes,
I don't think it's going to be easy.

Here, at the Royal Veterinary
College,

Alan Wilson's
colleagues are developing

a cat-tracking system that is
accurate to within centimetres,

incredibly lightweight,
so the cats will wear it,

with a battery life that will
last 24 hours.

Zach, come!

Cats are known to travel
up to 31mph,

often under the cover of trees
and undergrowth.

So Alan now has to analyse his data

and choose a tracker that is robust
and accurate enough.

And here it is.

There are 50 of them,

and the owners are queuing up to
get their hands on one.

Fantastic!

Give her another stroke.

Excellent, and let her eat.

Have one of these.
More food for him?

Amazing.

Within a few days, we've got
50 collars on 50 cats.

Everything is now in place
for the study to begin.

The scientists are setting up
base in the village hall.

The operation will run day
and night, across the week.

They've brought in an undercover
surveillance crew

so they can secretly film the cats.

We're having five more cameras dotted
around. One on top of the garage.

So hopefully,
we'll be able to see what's going on.

With the technology in place,
it's now all down to the cats.

The scientists
arrive at the village hall,

just as the first day's GPS
data is coming in.

261.

301, 302, 303.

Alan's team of engineers have
worked through the night,

wrangling the data and finding a way

to visualise the cats'
precise movements over 24 hours.

This is our village green here.
The deli's here, isn't it? Or here.

A detailed picture of the cats'
first 24 hours of activity

now starts to emerge.

Have you seen this one?
It's quite exciting.

Each cat is represented
by a different trace.

Brutus,
who simply patrols around his home.

Molly, who's drawn
to the neighbouring wood.

And Ginger, who heads out
to a neighbour's house.

The first question is, how far
they travel beyond the cat flap,

which is what scientists
call the cat's home range.

Sooty, who lives on the edge of the
village, grabs everyone's attention.

It's quite a big range. Hmm.

What do we know about Sooty, John?

OK, so Sooty is an ex-farm cat,

so that would figure.

Sooty has walked
two miles in the first day,

but he's gone just 160 metres
in each direction from his home.

Sooty's really covering
about three hectares.

He tends to travel quite a range
in this one particular time period.

But Sooty is unusual.

In the heart of the village

the average male cat goes
just over 100 metres from his house,

and female cats just over half that.

Some of our cats that lived
in this much more dense area,

actually how far they went was much
denser, was much closer, wasn't it?
Yes.

So the cat density is probably
much higher here than it is here.

And we've got a much wider
roaming on this particular day.

Another thing that's clear
is that these cats

seem to have distinct patches
that they roam in.

Some areas of the village

which apparently
aren't being used by the cats,

but then it may not be,
of course, a typical evening.

One day.
Not the greatest of weather.

So the secret world of cats
happens close to your back door,

just out of sight.

Even if they don't
go far from the cat flap,

they are still busy patrolling
round and round the same area.

Which do you think is
the one who's travelled furthest?

I think Sooty's the one
who's done most walking around.

What we're seeing here
on the screen is

the very first indication
we've ever had

of the detail of the pet cat's life
when it's outside the home.

Billy's travelled on this excursion
up to the farm and back,

but looking at Sooty, Sooty
may not have ranged quite as far

but there's a lot more loops here.

I think the fact
that we have got 50 GPS collars

on cats in this village
is fantastic,

because one cat's behaviour
will influence another's,

undoubtedly, when they're sharing
the same physical space.

Thomas is active nearly three
times - a little bit after dawn

and then in the early afternoon

and then a big burst of activity
in the evening, 10, 11 o'clock.

Quite a rush to get to this point

and so many things
could have gone wrong,

they don't seem to have done so
so far,

so I'm really pleased,
really excited

about what we're going to see
over the next week

and what data we'll get.

It'll be nice to see
as we go over the whole week

whether we see any usage in areas
we're not seeing
just after one day, won't it?

Oh, yeah.

So what are the cats
actually getting up to

when they're out on patrol?

In order to find out,

the BBC's research and development
department

has created a new type of camera

that will capture
a cat's eye view of our world.

Today, Dr Sarah Ellis and Alia
Sheikh, who developed the camera,

are out to test a prototype.

I wonder if that's recording.

Oh, I see, that's clever.
Is it recording?

It's recording now. Is it? It is.

The cat's welfare
is the first priority.

The cameras are very light,

and will be fitted
onto quick-release collars

in case they get caught up.

He's a good boy!

We'll give him
a bit of fuss, that's lovely.

And we'll play with him.

There's a good boy, such a good boy.

You're a good boy!
Are you wanting to go outside

and we can see what you're doing
with that camera on?

The cameras are then made smaller,

able to film in the dark,

even record sound...

..and then connected
to the GPS collars

so that we can see
exactly where cats are

and exactly
what they are looking at.

We've chosen 14 cats
to put cameras on,

and soon the world
through their eyes starts to unfold.

Hello, Coco.

How are you this morning, hey?

Yes.

Cats have excellent
long-distance vision,

but they can't focus their eyes
under 25 centimetres,

which is why they have whiskers.

They can jump up
to seven times their own height...

..and jump down much further.

So far, the experiment
has revealed just how close to home

most of the cats
in the village stay.

But as everyone knows, when cats
stray into each other's areas,

trouble begins.

GROWLING AND HISSING

For some cats, the privet hedges
and gravel paths

off our back gardens
are a battle ground.

There was one cat
that came into the garden.

It wasn't so much a fight, it was
a showdown between the two of them

sort of staring at each other.

He was out all the time, he
was like the king cat of the close,

and he was always fighting

and literally no-one would come...

Any other cat would be, like,
"Oh, it's Kato."

I heard this tremendous fight
going on, so I got the ladder,

climbed up the hedge

to see what was going on,

and the cat was having a fight
with the neighbour's cat

on top of the hedge.

On top of the hedge?

That was... Scarface? Scarface.

He does come in occasionally,

frightens the life out of them.

Charlie runs up the stairs to hide.

Scientists think that

many cats have a territory
much smaller than its home range.

It's territory
is its own personal space

where it eats, sleeps
and rears its young.

When another cat enters this space,

they instinctively
want to defend it.

CAT MEOWS

One of the questions
for the scientists

is how cats establish
and defend these territories.

Ginger has lived in
the village for ten years,

and seems to be
a pretty placid, well-behaved cat.

We think that he just goes next door,
catches the odd bird, and sleeps.

We don't think
he goes out at night,

because when you watch him,
he doesn't seem to like getting
his paws wet

or being out in the rain
or he doesn't like the cold,
he doesn't like the snow.

In the summer he'll just
sit and sunbathe in the garden,

so, yes, it will be interesting.

But appearances deceive.

Ginger, it turns out,
has a secret life.

Here's Ginger, he came over here
and if we just move forward.

The GPS data shows he's making
a deliberate, provocative journey

into another cat's garden.

To see what he's up to,
the scientists put a camera on him.

At 8.36pm Ginger leaves the house.

He spends a few minutes
patrolling his own back garden.

Then takes a trip
across the village common.

At exactly 8.48pm, Ginger stops...

dead in his tracks.

Just as he's entered
the other cat's garden.

And that cat is at home.

HISSING AND GROWLING

YOWLING

Eventually Ginger makes
a run for it.

HISSING

If you want to come in and have a
look, we've got some footage that's
come in on one of the cat cameras.

This is from Ginger,

and Ginger's been roaming
around the area near its house,

going through some fields.

Moving quite fast.

He's stopped.

You can see right away there,

there's a pair of eyes
from another cat.

HISSING

GROWLING

He's running towards the other cat.

I think he's trying to get
a bit of distance, really,

more than anything, because
the other cat came towards him.

Definitely doesn't want
to be anywhere near him anyway.

Wow! That's OK.

It looks like really a piece
of classic stand-off

between two cats,

where they are using hissing,
growling and yowling

to really try and keep
a distance from each other. Yeah.

And it looks as if
it was reasonably effective there.

And this is Tigger,

the cat whose garden he was in.

She lives in the house
on the other side of the common.

Didn't hear anything last night.

We do hear fights on occasions but
I didn't hear anything last night.

I'm surprised, actually,
because I always thought
that Tigger just let anyone in.

No, she doesn't. She does fight.

So this is how cats establish,

defend and even expand
their territories.

Our night-time pictures

reveal that these stand-offs
are going on all the time.

GROWLING

But although they found this
happening over and over again,

rarely did it lead to fighting.

They are descended
from a solitary species,

so if they blunder into one another,

then it's very difficult
for either of them to back down,

because turning your back on another
cat is a dangerous thing to do,

and most cats will have learnt that
very early on.

They would actively defend
a piece of land

which contains their core resources.

Cats do sometimes actually fight.

There are actual wounds,
claws and teeth get used.

But most cats will tend
to try and avoid conflicts

because if you rely
on yourself for survival,

it is not good in terms of fitness

to get yourself injured.
It's incredibly costly.

So this is a big part of what
your cat does beyond the cat flap.

Patrolling and facing off
the neighbours' cats...

..but, above all,
trying to avoid a scrap.

Big Ginge. Big Ginge! Pebbles with
a hat on, looking quite cross.

The way they avoid fighting
isn't just by having stand-offs.

The scientists think there's
something intriguing happening,

where the cats' spaces overlap
in the middle of the village.

This is Phoebe, she's
been living here for six years.

And this is Kato.

He's been here even longer,
and his owner wants to find out

why the two cats
have become permanent enemies.

He's got enemies across the road.
And do you know who that is?

Phoebe. Phoebe, OK.

Sarah thinks that
she may now have the answer.

The GPS data reveals
this is what Kato gets up to

over 24 hours as he travels
around the cul-de-sac.

And when you put Phoebe's
trace on the screen,

you get a snapshot
of HER daily routines.

So, in the green,

huge amount of overlap
in the space that they use.

There is, isn't there?

For cats,
which seek their own space,

these two cats are
on top of each other.

No wonder they are stressed.

But they don't seem to be
fighting much. So what's going on?

It's 11.50pm, here's Kato
heading out on his night patrol.

He stays mostly
around the cul-de-sac,

and takes a trip
into the local woods.

He comes back around dawn.

An uneventful night.

And that's because Phoebe
hasn't left her home all night.

But at 7.45 in the morning,
Phoebe heads out on HER patrol.

And Kato, he's at home.

Watching nervously.

A deeper look at the data
suggests that the two cats may be

sharing the same space,
but not at the same time.

Kato's out a lot, Kato's out a lot
late in the night here,

and a few short forays
in the morning.

Phoebe's active during the day,
and mainly after lunch,
in that period here.

Not much overlap
in when they're outside.

So when one was active outside,
the other wasn't.

So we think what they're doing is...
Avoiding each other.

Yeah. Using a shift system,

and the occasional time
when it doesn't work,

that's when you're getting a fight.
Right, OK.

So it's nice to know that
they have got the shift system

and they are managing themselves.

And it's not just these two cats.

Other cats, like Billy and Molly...

Interesting. Molly is out at one,
two o'clock in the morning,

a lot of activity here in the early
morning, when Billy wasn't out.

One's going in, one's going out.

..and Claude and Thomas
seem to be doing the same thing.

Claude comes over
into the area of Thomas,

Thomas is much further over,

they're not in the same place
at the same time,

they may time-share that area.

It seems to be happening
all over the village.

And here's how they're doing it.

A set of chemical signals
and scents which are secreted

from the cats' glands
in their cheeks when they rub...

..and from their paws
when they scratch...

..marks out who was where, and when.

If we imagine that the cat
is putting down a Post-it note,

it says what time it was there,
who it was,

and then it leaves that area.

Now, the nice thing about
leaving a chemical signal

is that you can physically leave,

but you have left a message
for another cat,

so when that other cat comes along

and reads that message,
or that Post-it note, if you like,

it's gaining information
about who is using that space,

and how long ago they were using it.

Sarah and John have believed
for a while that cats time shift,

to share space and avoid fighting.

But this data is the strongest
evidence they've gathered so far

that it's really happening.

The week progresses,
and the data continues to flood in.

The scientists have been looking

at how much time the cats
spend outside the cat flap.

The proportion of time
they spend outdoors

is actually quite low,

it might be as little
as 20% on average,

and some cats we know now
don't go out at all.

Even though
they have access to the outdoors,

they just simply choose not to do so.

At any one time, there are
many more cats inside than out.

Outside, the most we've ever really
got is ten cats outside at one time.

There's a nice place to rest at home,

they go out because they feel like it
rather than because they need to.

So the next question to answer is,

what has happened to the wild
sides of the cats of Shamley Green?

Cats haven't always been our pets.

We started living alongside them
around 9,000 years ago,

when we started farming.

And they had to work for a living.

We gave them food and shelter,

in return for keeping
mice and rats at bay.

It's the same reason these cats

live on David Hicks's
Oxfordshire farm today.

We were just overrun with rats
and the poison wasn't working.

They were burrowing under
the floors of the buildings,

undermining the floor
so the floor collapsed,

making holes in the bags of food,

and mucking and peeing in the food,

making it inedible for the animals.

We had such a rat problem,
in the end,

a friend suggested we got some cats

because they sorted
his rat problem out.

We're three, four years on now,

we've got lots of cats but no rats.

This relationship explains
why it was beneficial

for cats to hold on
to their wild side.

Cats like these must live

much in the same way
as we imagine cats must have lived

right at the beginning
of domestication,

when cats were first beginning
to associate themselves with man.

These cats
are really here as hunters,

they are here to keep the rats
and mice down on this farm.

And in that respect,
they behave much like wild animals,

they use the same hunting tactics
that wild cats do,

and every cat still has within it
the instinct to go hunting.

Cats are undoubtedly much wilder than
the average domestic animal is.

They choose their own mates,
who is going to father which kittens,

rather than, as with most domestic
animals like sheep or cattle,

or whatever, it's the farmer
that makes the decisions.

Cats are still really in charge
of their own destinies.

And whether they do become our pets

is down to how
they are reared as kittens.

There is really a very short window
of opportunity

during which kittens can learn
about how to socialise with people.

It's just between about four weeks
of age and eight weeks,

which is considerably shorter
than other domestic animals.

So if a kitten doesn't meet people
within that first eight weeks

then it essentially goes feral,

it becomes an animal which is
more or less like a wild animal.

It's still got
the domestic genes in it,

but it is, in terms of its behaviour

and its attitude to people,
much more like a wild animal.

This ability to tolerate humans

yet hold on to their wild side

was crucial
for the domestication of the cat.

Even if we think we've managed
to domesticate cats,

they still retain their wild sides.

And that's because
cats remain natural born hunters.

They're often vilified
for killing off other animals.

But the extent of this predatory
behaviour, in the UK at least,

is uncertain.

We found this mole here this morning
and we don't know if Ginger

caught it or not, but it's dead,
so we're going to pop it in here.

Pick him up so we can take him
up to the hall tonight

and they can have
a look at him up there.

The scientists are hoping
to use this study

in Shamley Green to see if there are
any clues as to what's going on.

It's a little shrew,

from Phoebus.

And he caught it
a couple of nights ago.

We've ask the owners
to collect everything

their cats bring home
throughout the week.

Lovely!

It's been in the freezer
for one night.

Probably died of old age.

I think he's been around
the gardens for ages.

Because cats
usually hunt out of sight,

often under the cover of night,

the scientists are hoping
the cat cameras and GPS collars

may help reveal
what they are up to.

When I came down this morning,

I opened the back door
and on the mat outside was this.

OK. On the back lawn, was it?

Yes, on the back lawn.

Think it's a bird.

He walked in very nonchalantly,
looking very satisfied,

so I went out and had a look, and
all that was left was one eyeball.

This is the green.

That's the green over here,
this is the other side of the road.

John, Sarah and Alan

have started combing
through the cats' traces

to look for unusual night-time
activity which may indicate hunting.

So that's Billy, and he looks
like he's travelling up to a farm

or a single household,
one single trip up and back down.

This is another cat
that he lives with, is it?

Molly's from the same house as Billy,

they're both British Blues,
pedigree cats.

This big trip is at night-time.

So I guess he's going to be
hunting up that hedgerow.

What he was doing at the farm,
of course, we don't know.

They were right
to suspect hunting that night.

Billy and Molly's owner has seen
the cats the following morning.

I think they were out pretty well
most of the night, actually.

I'm pretty certain they went out
as soon as we went to bed.

Billy in particular
came in with a very bloated tummy,

so I don't know
quite what he's been up to,

but probably eaten quite
a few bits and pieces along the way,

and he's very sleepy today. In fact,
both of them are very sleepy,

so I think they've been
hunting a lot last night.

They start to identify the cats

that seem to have the strongest
indications they've been hunting.

Like Sooty.

Spends quite a lot of periods
of time there.

Backwards and forwards
and backwards and forwards,

suggesting he may be using that
as a bit of a hunting ground.

A lot of time
and a lot of movement in that area

before he comes back down.

So this is very much a journey,

whereas this would be
more suggestive of hunting-type
behaviour,

just because he's covering
the same area a lot.

The next night, the scientists
put a camera on Sooty.

At night, cats' eyes
only need a sixth of the light
that humans need to see.

And what helps them hunt is they can
hear a broader range of sounds

than almost any other mammal.

He appears to be
looking for something in a tree.

But tonight, Sooty is not
successful.

The pub cat, Chip, spends a lot
of time in her neighbour's garden.

And here's why.

He climbs a tree
to get into a hedge...

..where there's a bird's nest
ready to be plundered.

The camera falls off so we don't
see the aftermath of his attack.

But we do have the evidence.

So by the end of the week, John
wants to know how many birds

and small animals
the cats have brought home.

And what, if anything,

it tells us about the true nature
of their hunting abilities.

We've got about 15 items here,

brought in by the cats, which
the owners have managed to collect.

The owners have also told us

that there was probably
seven or eight other things
that have been brought in

but have been consumed in front
of them, so a total of just over 20,

divided up between 50 cats,

so that's less than half a prey item
per cat over the whole week.

It's not a huge amount.

I don't think our cats
are hunting very seriously.

They obviously spend
a lot of time out of doors,

or at least many of them do,
looking around,

as if they're hunting,

but the actual pouncing attempts
are comparatively rare.

There's a couple of birds actually
been eaten, at the back here,

a house mouse, just one, which
is the traditional prey of the cat.

That's a vole, and here, almost in
pride of place, is a mole,

which is very difficult
to catch for a cat,

because of course they spend
a lot of time under ground.

This is no more than a snapshot

of what's going on
over one week in this village.

But while we've been here,
the impact has been rather minimal.

So what might be going on here?

It could be that
this year's cold spring

has delayed the birth
of the baby animals.

Or that cats just don't like
being outside in bad weather.

But the data from the experiment
has thrown up

an even more
intriguing possibility.

When Coco's GPS collar
is first turned on,

she's in this house,

and it's not hers.

On Tuesday, here's Chip.

Again, he enters
a neighbouring house.

And a day later,

here's Claude doing the same.

It's only when
we install surveillance cameras

by the cat flaps that we see
exactly what is happening here.

Rosie has her evening meal.

And then half an hour later,
her neighbour, Claude,

boldly enters her home

and helps himself to the leftovers
when she is out of the way.

At 3pm the next day,
he's at it again.

And it won't be the last time.

It's a bit of a surprise
to Claude's owner.

Three minutes of scoffing
in Rosie's house, non stop.

How embarrassing.

We've watched this video
several times,

and he doesn't spend much time
lifting his head, looking around.

Worrying about anything.
Exactly. He's at home.

This is normal. I feel that
he's confidently doing this,

and so he's done this
probably more than once,

this may be routine for him.

Oh, dear.

So, yes, midnight snacking
is definitely happening
in Claude's life.

I think one of the things
that I've been surprised by

has been just how many cats
are going into other people's houses.

I'm not sure yet quite how
many of those people are aware

that those cats are coming in,

but one of the main reasons
they come in will be to get food.

They'll be stealing food
from other cats, essentially.

I think you can almost bounce that
off against the rather small numbers

of prey that we've seen this week.

Some of that may be
down to the weather,

but I think a lot of it is

these cats are getting a varied diet
by raiding other people's houses,

they don't really need
to go out and kill things.

Over the past decade

pet food has become more nutritional
and more common.

So perhaps
what we are witnessing here

is cats changing their behaviour
as we change their environment.

But there's another part
of the cats' secret life,

where they've adapted
to being more like our pets,

and it's to do with
how they communicate with us.

This cat meows a lot.
They both purr.

If he's got no-one to play with
and he's just on his own,

he'll walk around -
meow, meow, meow, meow -

until someone comes.

Sometimes, I can hardly hear it.

IMITATES SOFT PURR

And sometimes it's...

IMITATES LOUDER PURR

..this sort of thing.
He does have various purrs, yes.

We may think cats are our pets,

but many owners are left
with the uncomfortable feeling

that the cats
are really calling the shots.

We tend to fit in with
the cat's lifestyle.

Very much so.

The cat's in charge?
No doubt about it.

It probably makes us quite unique,
in some respects. Do you reckon?

I reckon, most households,
I think the cats are in charge.

Not quite as much as this one,
I don't think. Yes.

This is very much
a feline-focused family, we are.

By his purrs,
I know more or less what he wants.

They get their own way

because as cats
have become domesticated,

they've learnt to change
the way they communicate.

When an animal meows

or purrs, we tend to
verbalise back to that.

And it's almost like we have this
idea of there being a conversation.

And I think
that definitely does

have a part
in strengthening the bond.

Sarah Ellis
is going to repeat an experiment

first conducted at the University
of Sussex on her own cats.

It focuses on
two different types of purr.

She's going to record them

to find out what makes purring
such an effective way

for cats to get our attention.

The first is
the non-solicitation purr.

GENTLE PURRING

The non-solicitation purr

will be the one that people
are most familiar with.

That's the purr that cats do
when they are content, relaxed,

when they're being stroked
or interacted with by their owners,

or if they're sitting on your knee,
for example.

In you come, good boy.

But scientists
are particularly interested

in another type of purr,

the so-called solicitation purr.

Cat owners will definitely
be aware of this,

but it may not be so well known
amongst non-cat owners,

and this is the purr
that cats do

when they want something
from their owners,

and very often
that is in anticipation of food

or if you're preparing food.

LOUDER PURRING

It's constantly
chopping and changing

the length of those purr bouts.

And the purr is much faster
in certain parts, isn't it?

Back at the lab,

Sarah's colleague examines
the frequencies of the purrs.

At the top, we've got
the solicitation purr

and down below, we've got
the non-solicitation purr.

Both of these
are low-frequency purrs,

but what particularly stands out
quite clearly

is that complete stand-out peak you
can see with a solicitation purr.

It's very isolated from the other
frequencies around it,

which suggests it would
really stand out quite clearly.

You don't see that at all
in the non-solicitation purr.

And there's a surprising
reason why we react so strongly

to this frequency in the purrs.

Because embedded within it
is the same frequency

as a baby's cry.

As humans, we are
more sensitive to vocalisations
in that frequency range,

and we're more likely
to respond to them.

And that's likely
because it taps into
our care-giving or nurturing need,

and it's this, I think,
that makes them so successful

at being our pets,

because they have to
illicit care-giving from us,

and they've become
very, very good at that.

The experiment
is drawing to an end.

The scientists
are starting to see the ways

in which cats' behaviour
is shaped by us,

and by all the other cats
living so close by...

..how they've created
tightly packed territories...

Todd came up here, really close
to where Thomas has been.

..how they may be time-sharing
to avoid fighting...

..and how they may be hunting less
and eating each other's food.

But there's one surprise
left in the village.

This is the Edwards' house.

And they have not one but six
unrelated cats living together.

Meet Duffy,

Patch,

Daisy,

Coco,

Pumpkin

and Ralph.

They seem a pretty happy lot,
and given that the cats

are both solitary and territorial,

they do seem
to get on pretty well together.

But no-one is sure
what happens beyond the cat flap.

Yellow's Daisy. What colour is
Pumpkin? Pumpkin's pink. Coco is red.

So while Patch roams
the local neighbourhood,

Duffy, Daisy, Coco,
Pumpkin and Ralph

are all out at the same time
and sticking very close together.

Which is a genuine surprise.

Your cats
are actually really interesting.

Down in the village, we've got
lots of reports of hostility,

including fights, and in a
multi-cat household, which you have,

you're our largest number
in our study, with six cats,

we would expect there to be
quite a bit of tension,

quite a bit of
using different space outside.

What's really, really unusual
is we don't see that

with your cats at all.

And apart from Patch,
who is the blue,

and he does have a further range,

he does go much further
than the others,

they're very, very much centred
around your home,

around your garden,

and the really interesting thing is,
they're all there at the same time.

Fantastic. None of them
are moving particularly quickly,

they're all just bumbling
around together, really.

That, for us, is fascinating,

because a whole group
of unrelated cats...

we just wouldn't
necessarily expect that at all.

Out of all the lot we've had,

this has been the ones
that have gelled the most.

Especially the boys,
they're always...

You'll see them playing together,

they will lie together.

Pumpkin and Ralph lie on top of each
other, not just next to each other.

It's so cute the way
they get on so well together.

Do you ever see them rubbing
their faces against each other? Yes.

And Pumpkin and Ralph spent
a lot of time grooming each other.

This cat camaraderie is another
example from the experiment

to suggest that cats
may be changing,

evolving away from hunters
to fit in better with us.

As we're domesticating cats,

we're retaining a lot more of

what we call
their juvenile characteristics.

So they purr a lot, they play a lot,
we see them needing behaviour.

With our pet cats,
if we are domesticating them

and they are evolving, in a sense

that they are retaining
lots of these characteristics,

they might be more likely to be able
to get on with each other. Yes.

But we're right
at the cusp of that,

in sort of
the domestic cat's evolution.

If she's right,
this sort of feline harmony

could be a vision of the future,

as cats evolve
to please the hand that feeds them.

At the end of the week, the team
have pieced together

a picture of what the cats of
Shamley Green

get up to
when they leave the cat flap.

Look, she's gone so far!

The scientists have seen
that all the cats

have very different routines
and roaming patterns.

One of the most stay-at-home cats
is Brutus.

Didn't think he did,

but now I've got the proof
he doesn't go very far,

so that's reassuring.

And Hermie is definitely
our roamer of the week.

From the top to the bottom,
that's 300 metres,

it's 200 metres across,
so that's six hectares,

15 acres which
he's actually ranging over,

he's really going
a long way overnight,
covering a great deal of distance.

Quite exciting.

I had suspicions he may have found
himself a sofa in the village

that he likes to sit on,
but evidently not.

The remarkable thing
about this study

is its sheer size
and the accuracy of the data.

Because we're looking at 50 cats,

you can start to look at a lot
of different effects in the data

which you just don't get
with a smaller study
of five or ten animals.

So this has come together
really nicely

to give a dataset that's a size
that you can actually
make those comparisons of.

And what the scientists are seeing
is a community of cats
that is changing.

The cat,
when it goes through our cat flap,

exhibits some of the behaviours
of its wild ancestors,

such as hunting,

and then it will come
back through our cat flap

and have a social bond with
the owner and be a family pet.

Cats are still evolving and probably
will still evolve into the future,

becoming much more pet-like animals,

and will lose
some of those wild instincts

because many of those things
don't actually serve them very well
in the 21st century.

Perhaps cats will become less wild
and even more pet-like,

because that, it seems,
is what we want them to be.

And if you want to follow more
of our cats' journeys

you can log on at...

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