Thanks for all the replies and ideas. I am not sure that they live in caves but only hypothesized they might because their eyes and movement seem to be like no other primate. Usually environment dictates adaptations, so if they simply lived in the woods like other primates I wonder why their eyes are so reflective and why they are so large, strong, flexible and agile. I surmised that these features are ones a carnivores cave dweller might have evolved to have over many years. For example, navagating the caves in darkness and even using their strength to manipulate the caves and yes, hide the entrances. Thanks again.