I used to be scared to walk into the woods in the dark, still am sometimes mind likes to play tricks or the imagination starts to go into over drive. The woods are alive at night it is amazing how much different things seem to be in the dark woods. I would just spend lots of time taking him to the woods start with the day and describe all the sounds he hears then slowly work your way to dark don't push just let him know that the sound he hears is just an owl or a rabbit. and when next spring/summer comes around take him camping lots. and by next season he should be able to control his fears if he still has any. Most of all keep letting him know and if possible show him that most every animal is more afraid of us they we are of them. Good Luck ( DO NOT LET HIM WATCH BLAIR WITCH OR FRIDAY THE 13TH ETC THAT WILL PRETTY MUCH END HIS WALKING IN THE WOODS DAYS FOR A VERY LONG TIME BLAIR WITCH STILL GIVES ME THE WILLIES JUST THINKING ABOUT IT)