RE: Do deer have a 6th sense?
I don't believe that they do. Obviously their senses are more attuned than ours, we don't have to walk around on a daily basis worrying about a cougar jumping down our neck.
I think what is called "sixth sense" is really sounds, smells, and sights that somehow bypass our conscious processing, but still register somewhere in the back of our brains.
F'rinstance, I woke up bolt out of bed on Sep. 11th just knowing that something bad had happened. I don't usually turn on my radio first thing, but that day I did. Of course, the airways were full of news of the developing horror. I could claim some psychic sixth sense out of that, but I think it's probably more mundane than that. I work a late shift so I'm in bed until 11 am or so. I think that even though I was asleep I probably heard someone talking outside my apartment about it.