It was a dark and moonless night, with no wind. Just before midnight, I was awakened by a loud noise outside. I know that some animals (like rabbits) can make strange squeals if they are captured by a predator, and that was my first thought. I grabbed a video camera, turned on the porch floodlights, and looked out the window. Nothing visible. The sound didn’t change, so I stepped outside with a strong flashlight and went towards the sound. The sound didn’t seem to care about my presence.
I was able to trace the source from somewhere in the trees, perhaps 20 ft off the ground, but was unable to find anything visual, so the video shows nothing useful.
I kept the camera running for a few minutes, but the sound continued for at least 3 hours, diminishing, but never changing the apparent source direction.
So what is this sound? (The first 3 minutes are the best.) And why would it do this from midnight to 3AM, never moving?
The white noise you hear is from the Lake Michigan waves nearby, and the loud bangs are my screen door closing.