So she came to us as a stray before we decided to bring her inside.

Is it like a mystery to you, like what her life is like out there?

Oh, yeah, absolutely.

I found out about mom and study, and so we signed her up.

So this is the tracker that we are using on the cats.

What we have here is the microchip that has the accelerometer, and the GPS.

The accelerometer measures the cat's movement left, right, forward, reverse, and the GPS tells us where the cat is.

Should we release the kraken?

So glad I got to say that.

I think this is kraken right here.

It went down here to this house and then it came back.

And you can see the one track way over there, that was a bit of a surprise.

Rollands study isn't just the biggest study of cat movement in the world.

It's the largest tracking study of any species.

Rolland sent GPS collars to collaborators all over the world.

So this is just a map of the Earth and I've got pink dots anywhere that we were tracking cats.

So we've got Ali Aly, Amber-Rose, Amelia, right, just A to Z probably.

We've got all kinds of different, different ones.

It turns out most cats don't stray too far from home.

Our average across all 900 cats was 3.5 hectares.

That's about six or seven football fields.

And the next thing we had to figure out is how do we put that into perspective?

Roland compared data from domestic cats to their closest wild relatives.

What we found was that the domestic cats have a 4 to 10 times more ecological impact on their prey then do wild species.

But that's going to be concentrated within basically 100 meters of someone's house.

One of their biggest footprints can be seen on migrating bird populations.

There are some estimates in the United States that cats kill sort of 1 to 3 billion birds a year.

Billion?

Yes.

But it's even more small mammals.

It's like 7 to 10 billion small mammals.

And the impacts of cats in places like Australia, New Zealand, and Oceanic Islands have been devastating.

There are examples of animals that have been completely hunted to extinction by cats.

Some biologists consider them the worst invasive species alive.

But Roland's got a plan to curb the impact of these cuddly killers.

It starts with the accelerometer in the collar.

The accelerometer basically measures the orientation and the movement of the collar in three dimensions.

So here you can see.

Look how rhythmic this is.

Okay.

So that's a walking or running cat.

If the accelerometer can recognize a walking or running cat, what else can it tell us?

And so what our goal is to get artificial intelligence algorithms on the caller recognizing this cat's about to hunt so we can have basically a bird alarm call go off on the cat's collars and all the birds would be alerted.

Look out, predator here.

That's brilliant.

So that's thinking that that's really cool.

That's one idea.

We've made a pact with cats.

Even as they deplete the natural world around us, they seem to enrich another part of our lives.

Sure, their modern existence can be pretty bizarre.

And damn, do they make my eyes itch.