The Ghosts of the Jungle
Even though it is true that many people who have not returned from the jungle have fallen prey to animals and other natural dangers, it is quite sure that not in all cases this explanation is applicable. For all we know it is quite certain that there have to be other dangers in the jungle than such mundane ones. How can it be explained that several watchmen of expeditions have vanished over night while none of the people asleep in the camp was harmed? How is it possible that well armed and seasoned adventurers got lost in the jungle? Considering the expertise of some of the victims this jungle has taken, it would be highly ignorant to assume that a simple beast of some kind could be the source of their ultimate doom. In conclusion we have to assume that 'something' is out there. A malicious, unseen power. Never seen but often felt. Noticed only by the 'inner eye' but never actually seen. Everybody that has ever set foot in the jungle knows this eerie feeling of being watched and traced. Sometimes you can almost imagine the movements of something invisible in the bushes.
And do all those glowing eyes in the darkness belong to animals? I don't think so.