The cat looked at a leaf as it skittered across its vision. The leaf snagged on a piece of sidewalk, then leapt forward, tumbling end over end, flashing its light underbelly as it pirouetted down the street. The cat’s tail flicking in irritation – was trying to stalk someone, but the leaf couldn’t be ignored. Even after decades of hunting live prey, the erratic, crinkly movement demanded attention from synaptic pathways encoded millennia ago. (( reword synapse bit to be more animal, less scientific. ))
From the cat’s perch – a high, flat-topped wooden fence, overlooking a single-car sidestreet – it could see the dentist’s office, where its quarry spent their own eternity. The cat had already tried attacking them, but the human had just protected their face and kept walking, accepting every bite and gouge with a muffled yelp or wince; but they never bothered to properly defend themself.
Probably they were as immune to serious harm as the cat itself.
It couldn’t remember how long it had known this, but the cat wondered why the human was the only other living thing that would not die. And why it felt the human had wrong it somehow.