On the conservatory window we have one of those stick on bird feeders. It's great for watching the robins pop in and out and the pigeons can't get at at it.
The other day we were surprised to see a squirrel shimmy up the drain and try to get at it from the roof. It didn't do very well so we took pity and put some food out at ground level. Sure enough it came back and spent quite a lot of time eating. Somehow it seemed desperate.