My friend Daniel and I lived in two separate single wide trailers available for employee housing. Both were heated by an outdoor boiler that we needed to stock with wood a few times a day. We were the only ones living on the compound since it was winter and off-season. We went out to stock the boiler and it started snowing these insane huge snowflakes out of no where. Beautiful. We sat and watched the snow, amazed. After we had put a grip of logs in the boiler we heard this sound fly over us. Close enough we could feel the vibrations in the air. It sounded like something that flapped its wings at the speed of a humming bird but was much larger. Much larger. For something to flap its wings that fast and be the size of it that it was...we could not fathom what we felt and heard pass over our heads at a close range, twice. Middle of winter, mind you, in a snowstorm. If birds were out (why would they be in the middle of the night in winter???) we couldn't think of a single species that flapped its wings like that that would be that large. We could FEEL the vibrations of the wings against the air. Unexplainable. We sat in dead silence, crackling of the fire is all we heard...nearly an OZ effect. Sitting in silence for what seemed like forever just staring questioningly into each other's eyes, a definite WTF WAS THAT moment. We talked about it for a long time. Never saw anything, just experienced sound and feel.