Our bathroom window has frosted glass. Light gets in, but you can’t really make out the details. We hung a bird feeder just outside so that when the window was open you could watch little birds eating.
The birds are usually pretty paranoid. They spend about 90% of the time looking around to make sure the coast is clear. (The other 10% is spent jamming their heads into the feeder holes and shaking out as many seeds as they can, wasting our generous offer by spilling it onto the ground.) They’ll be happily making a mess one minute and all fly off in a hurry the next.
Usually it’s nothing, but the other day I saw a big dark (frosted) shape on the other side of the glass when the flock took off. I got up to check it out and saw our neighbors’ fat bastard cat looking smug on the edge of the garage roof, about a paw’s swing away from the feeder.
I called Sarah over and she told him to piss off. He did, but didn’t go too far. That’s him in the background with the feeder in the foreground. (It’s all blurry because of the screen.)