Haunted Walk

Last weekend, and for the next 2 weekends, there is a haunted walk on campus in the nature trail. When helping to set up, a long black snake slithered in front of me and into the nearby brush. It really scared me, especially since I was in the middle of the trail with no one around. I like the concept of the haunted walk. Just being out in the trail, surrounded by woods, in complete darkness makes it so much more frightening than it really is. What is it that makes nature so scary? Is it just because it is not familiar? I think so.