I despaired of finding a sticker for my patio doors, so I made one with the plastic coating that you can cover books with, and put some little glittery stars in in, cut it in a circle and clapped it on the door! We have now got a craft shop in town, and they sell peel-off stickers which are nice, so low down on the doors (ie at Cocker eye-level) there are butterflies !!
Mind you, they blodge their noses on the glass so much when they are peering out at the garden that I fail to see how they can mistake an open window for a shut one, given how smeared they get !!