I live on the third floor of an apartment block.
There are no flats above me, no one in the block (to my knowledge) owns a cat, and I don't see how any neighbourhood cat could get to my balcony.
Which is why I'm utterly at a loss to explain the BONES LITTERING MY BALCONY.
The bones appeared singly over the past month. Since I can't see how a cat could get onto the roof of the apartment block (there are no adjoining blocks with rooves high enough, and no trees the cat could climb that would deliver it so high), I'm forced to consider alternative theories.
Like cannibal birds.
I see a lot of birds sweeping in and out of my view. They love to roost on the roof, however briefly. Mostly pigeons, mynah birds, and ravens. And since the advent of the bones, I am now wondering if they're not EATING THEIR OWN KIND UP THERE.