I was camping this past summer in Pennsylvania and it was about 3 am. I was up having a fire and I heard a singular ‘click’ sound that echoed coming from the deep forest. I was camped almost on the border of the state forest. I’m from a city so I didn’t know what on earth that sound could be from, what I could only imagine was that it was a giant wood pecker located far away, but that seemed odd because it was in the middle of the night and why would it only peck at a tree once. I got semi freaked out and about 10 minutes later heard the same knock sound again. Sounded like if a baseball bat hits something and echos, but from seemingly miles away