Most times when you visit the zoo animals are subdued and don't feel like being bothered with. You are excited to see certain animals then you get to the cage and watch them for like 3-5mins. They don't really move around and your excitement dies down as the time grows.
Every once and a while this moment happens and it is pretty awesome to see.
Literally had this in my head, how could you not have The Jungle Book in your head after looking at the video!