I was surprised to find that if I put a little bit of bird food on the deck, the squirrels will come right up to the screen. They earned their keep, it's the only thing that will keep these little stinkers occupied for more than 5 minutes.
You could have carved the kitty tension with a knife. Lots of chitter-chattering, meowing, and tail-swishing. But the squirrel was Joe Cool and didn't seem phased at all. At one point, they were even sniffing each other through the screen!