Again, I can only offer anecdotes. My cat will react to unusual movement outside a nearby window even when he's curled up with his eyes closed. I remember one

Again, I can only offer anecdotes. My cat will react to unusual movement outside a nearby window even when he's curled up with his eyes closed. I remember one instance in particular where I was playing music fairly loudly. He had his eyes closed and was lying down facing away from the window when a dog walked past. His ears perked up and he immediately got up and looked around. I can only assume it was the sound that tipped him off. It's not necessarily that their hearing/smell/vision is so much better than ours, but rather that it's more specifically evolved for their role as predators (as another poster pointed out).