While our brains get swamped with information about patterns and colour,
through Kali's eyes, fast movement trumps everything.
As she stalks the flies, her eyes send signals to the brain's visual cortex,
which analyses what's changed between one picture and the next
up to 70 times every second...
faster than the human brain.
And a far bigger proportion of the neurons in Kali's brain
are dedicated purely to the detection of movement.
She almost can't help but pounce.
Cat's wild ancestors relied on low-light vision...
and the ability to detect movement to stalk prey.
But these evolutionary adaptations have a downside.
Cats can't focus on anything closer than around 30 centimetres in front of them.
But where their eyes fail them, cats have another perfectly adapted sense
to go in for the kill.
The team have set up an experiment
to reveal just how our cats' secret weapon works.
The camera can do in full HD resolution up to 2,700 frames a second.
I would have thought 20 to 30 times will get it.
Also the camera...
John Bradshaw is hoping these ultra-high-speed cameras
will capture this extraordinary sensory organ in action.
It really is very, very quick.
I've seen still photographs of it happening,
but there's nothing like actually seeing the whole motion.
So, I think we got it there, but it is very, very quick.
John's trying to observe the cat's whiskers
as they move forward into the attack position.
Let's just take the toy away for a second and let's...
Can we have a look at what we've just taken?
Okay, so here we go.
The cat realises the mouse is within his grasp,
but he wants to know exactly where it is in relation to his mouth.
Its eyes give up because they can't focus very close.
That's where the whiskers take over.
So, what we can see here is the whiskers suddenly being swept forward.
And now the claws are coming into action.
So, what we've got here, look.
The whiskers are pointing almost directly in front of the cat's nose.
In fact, he's catching them with his claws as he sweeps round
trying to catch the mouse.
But the little muscles at the base of each whisker
are really tugging hard to swing those forward
completely out of the normal position.
This is really extraordinarily detailed.
I'd never expected to see all of this.
It all seems to take place in about a fifth of a second
which just shows how fast cats' reflexes really are.
From the point where they sweep the whiskers forward,
where the muscles contract, and then relax back
and the whiskers spring back again, the mouse doesn't have a chance.
Far thicker and longer than normal hairs...
whiskers also sit three times deeper in the skin
where they attach to nerve endings,
telling the cat how far each one is being bent back and how quickly.
Their whiskers are the same width as their body...
allowing cats to navigate the narrowest spaces.
Cats also have whiskers above their eyes and on their ankles,
sending them a constant stream of information,
as they sense the world around them.