http://www.youtube.com/watch?v=UVjNPGWdwFI While not my video, I heard pretty much the exact same sound about 1:20yesterday morning while in the stand. I never saw the hog. Later I went back and checked my game cameras and the only hog that showed was a decent-sized nursing sow. I had been told that this sort of angry grunt is a male only trait. Does anyone know if this is a valid claim? If it is a grunt of anger, I am not sure whatI did. The hog grunted once whilst off in the distance and before getting close to my location. About 20 minutes later and very close, made the noise again but kept rooting around for a bit until stopping, giving me several of these grunts, then running off, stopping, grunting, running away further, stopping, grunting, and running off again to a point where I no longer heard a thing. Any insights into the noise and who makes it would be helpful.