The last thing you want to hear in the middle of the night is the sound of high-pitched grinding floating through the trees. To me, this would signal the imminent invasion of aliens and I would be out of there in a flash.
However, Redditor enamore22 stood their ground, grabbed a camera, and started filming. While we never see anything extraterrestrial in the footage, the sounds are disturbing to say the least.
Take a listen for yourself in the video below.
The Redditor says the sounds went on for about 15 to 20 minutes before stopping. According to one commenter, what we're hearing here is not aliens. It is actually a manual test to calibrate a nearby AM radio antenna. This is usually done during the day when people are at work, but this must have been an emergency situation.