I run six trail cameras in the southern unit of Wayne National Forest and I want to be clear up front: in four years I have never gotten a usable photo of anything I couldn't identify. This isn't that report either. This is about sound.
Last October I was packing out after swapping SD cards, maybe forty minutes before dark. I heard a single sharp knock from the ridge across the drainage — like a baseball bat against a trunk, once, clean. Woodpeckers don't sound like that. A falling limb doesn't sound like that.
On an impulse I picked up a branch and knocked twice on a beech tree. I waited. Two knocks came back. Same cadence, same spacing, from the same ridge.
I did it once more — three knocks. The answer took longer this time, maybe thirty seconds, and it was three knocks, but closer. Whatever was answering had moved maybe two hundred yards toward me in silence, across a slope covered in dry leaves that I couldn't cross quietly on my best day.
I'm not ashamed to say I left. Fast walk, not a run, checking behind me the whole way. Nothing followed me to the truck. The cameras got nothing that night — whatever it was stayed out of every sight line, which given where I'd hung the cameras is either luck or it knew where they were.
I've been back since, in daylight, with company. But I don't knock anymore.