When I went to greet the chimpanzees this morning they were both outside. Loulis was lying down on the cement steps but after a moment he bronx cheered to get my attention and initiated a rowdy game of chase. Then I grabbed the huge stuffed gorilla we have and pretended that it was chasing Loulis. He seems to like playing that game with me and we enjoyed it for quite awhile.
At one point, from the West playroom, Loulis saw (over my shoulder) Tatu running in from outside. As soon as he saw her running in toward the West playroom he backed away quickly from me and the giant gorilla and started making noises as if he were scared of us. Tatu came running in, touched his shoulder as she ran by, and banged and poked at the gorilla while threat barking. After she had done this, she reached out a hand to Loulis to give him reassurance. Good thing Tatu was there to take care of business!
pan.bloglodytes 
Well now I want to know – why would Loulis all of a sudden act as if he was afraid when he’d just been playing as if nothing was wrong? And do Loulis or Tatu ever ask or speculate as to why they stay on one side of the gate and the “humans” stay on the other?
It is difficult to speculate on the why although it certainly appeared purposeful at the time. Perhaps he simply wanted to include Tatu in the game?
Unfortunately, I don’t have a satisfactory answer for your second question. Tatu and Loulis are not generally interested in discussing the why of things in conversation but the absence of the topic isn’t necessarily evidence that they don’t ever think about it.