I've hiked at night many times since LED headlamps came about, most of it bushwhacking in thick forest.

I've noticed more water moccasins out while night hiking. They do tend to cruise the stream banks more then, especially in areas where there's lot's of vegetation. I suppose the copperheads might be out more then. I almost never see them but a couple years ago we had 9 people bit after dark in one weekend around here. All of them stepped on the snake, most were in their own yard, none were out hiking.

Other than that, I can't say I've noticed anymore wildlife out and about.

I've never got or worried about getting lost but I tend to use the terrain to navigate night or day and I usually only hike a few miles at most during night hikes.

One time I did have a bit of trouble finding my car at night after bushwhacking all day. I knew I was close, even had it way pointed on my GPS, but it was parked in thick brush and it took me a bit to find it.