What "happens" in the last paragraph of "Sounds"

Late at night, he hears distant wagons going over bridges, baying dogs, perhaps another cow, and along Walden's "Stygian lake," bullfrogs, whom he imagines passing a cup in a medieval banquet under the surface of the lake, bellowing "troonk." Though he never heard a cock's crow from his cabin, he suggests that the rooster (whom he calls "cockerel") be naturalized, so that his call would call everyone to awakeness. But in his cabin, Thoreau had no "domestic sounds," no roosters, cats, dogs, or even rats in the walls. Instead, his sounds are squirrels, whippoorwills, owls, loons, and foxes. Instead, nature reaches right up to his door. He doesn't have to worry about digging a path through the front yard in a snowstorm because he has "no front yard,--and no path to the civilized world!"