Re: Whee are the aliens?
We are in a region that is completely empty.
How do you know that? We've not yet ruled out civilizations around the closest stars, we've got more to go to rule out a dead ancient Martian one and we will probably never completely rule out past visits to the Solar system or leftover alien artefacts on Earth and other bodies (well, if we discover that the area is completely desolate presently and historically, they will kinda rule themselves out).
We don't know that yet. At least not for sure (though I suspect the same as you).
R.I.P. Admiral James T. Kirk (2233-2267, 1969, 2267, 1930, 2267-2268, 1968, 2268-2269, Serpeidon Middle Ages, 2269, 2237, 2269-2286, 1986, 2286-2293, 2371)