Here's my cat, stalking the first visitor to my balcony garden that was out there while she was - a fly. Notice her stealth moves. Not bad for just three legs! The cat that is, not the fly.
And being that flies have wings, it's here then gone but she enjoyed the chase and that's one of the reasons that I have decided to build this balcony garden - it gives her something to look at while she is in the house looking out the window and something to interact with when she is out on the balcony with me. I NEVER let her out on the balcony unattended. I don't want her to eat anything she shouldn't AND cats being cats, I don't want her to somehow jump up (even though she only has three pins and is missing one of her back legs, if a pigeon or something else equally tantalizing landed on the net I would not put it past her to jump on it and then down 19 floors). Oh yes, it could happen, with this cat, that's for sure. She's a real hunter, back from her alley cat days (she was a humane society kitty).
So for her safety and to keep the pigeons out of my lettuce (last year I awoke and looked out my window to see my beautiful basket of full grown lettuce being used as a nest by a pigeon!) I threw out the basket and the lettuce and that was that - a net was implemented! I had a pigeon net professionally installed. Best money I ever spent.
So even though she cannot sit on the ledges of the balcony, she quite likes just looking through the space between the railing wall and the concrete floor where she stays cool in the humid heat of summer as she enjoys watching the doggies and people walk on by nineteen floors below.