This summer I saved my pennies and finally splurged on a set of birding by ear modules, which I downloaded into my iPod. Being the bird nerd that I am I often listen to them while driving or sometimes while I work (although it is odd when I accidentally hit the Shuffle button and have the Dave Matthews Band followed by bird sounds of the Southern New Jersey Salt Marshes.)
The Hummingbirds at the feeders were too busy stocking up for their long flight south to pay much attention, and the House Sparrows and Starlings and Robins just went about their business as usual. An Indigo Bunting sat atop a tree and called "Sit, Sit, Sit, Sit", several Barn Swallows dipped and dove, and most of the morning sounds were normal. But I knew something was back there, just from the sounds.
Earlier in the morning a doe with her triplets came close to the house to browse, and seemed unworried. And although I've heard Black Bears are back in KY now, I've yet to see one. My bet is a fox, although if they're smart they'll stay in the woods, as our Livestock Guardian Dog Toby has no patience with foxes near his goats.