More than likely a screech owl nearby. Did you see the movie, "My Cousin Vinnie"? When Vinnie was sleeping in that log cabin in the woods in Alabama and heard a screech owl he went out on the porch and fired off six rounds from a .357 magnum.

Well if that turns out to be the culprit, I give dees the credit, since she (or he) first suggested the nighthawk. I'm not very good at onomatopoeia: TCHK or "peent" . I have enough trouble spelling actual words, much less trying spell random strange animal noises. :-) I remember watching nighthawks in Ohio, climbing into the sky and diving, over and over, late into the night until all you could see was the two white bands on their wings. I also remember seeing (and hearing them) in Minnesota when we lived there. I don't think they live in Virginia near me.

It's more than likely a bachelor mockingbird singing for a mate! Once paired, the midnight serenade will end. Mockingbirds are aptly named due to their ability to mimic any noise they hear that they find beautiful including other birds, and other creatures like bugs, frogs, even emergency vehicle sirens! A male mockingbird will continuously add to his song throughout his lifetime, and no two mockingbirds have the same call! The male we had this year repeated a cardinal call, a Carolina Wren, and a tree frog, and then multiple others I couldn't identify.. He probably sang for a month, then one night he was gone. I only looked it up because I Know a cardinal call and couldn't figure out why on earth a tree frog and a cardinal were talking to each other at midnight on my back deck!

OK, I think I found it. I think it's a fledgling begging call of a Barred Owl. It had the definite rasp of this one and the ascending scale, and even sometimes how it would come out more like a whistle. Barred Owl