Deer startled by mysterious object hitting camera from above

I have had this video for years and had never went all the way through to the end. I normally scan for buck videos so don't pay too close attention to others but should in the future. Something definitely hit the camera which is located about 10 ft from where the nearest deer is standing. Most likely a squirrel from above had something to do with it because not too much else could get that close to deer in the first place.