I've seen monkeys and chimpanzees do that. I found a high rez photo of her online doing that http://4.bp.blogspot.com/_MEutUUaaZEw/TSvU5TAH_hI/AAAAAAAAFy8/jEJNcKWFh2I/s1600/gorilla3.jpg https://youtu.be/XofxIYyvZ1s