“It’s interesting that animals ‘Play’ - even after they are adults.”
We have five cats with ages ranging from 9 to 12. Every once on a while the usually-lazy critters will get motivated to play in a pretty crazy way. It’s fun to watch, and make us believe they’re happy.
We don’t really understand animals. From our observations, we come up with designations and words, like ‘instinct’ and ‘behavior’. But we’re looking from outside-in.
I think there’s a lot on the inside that we are still far from understanding.
People who own or otherwise live intimately with animals - and *love* them - probably have a much better sense of their natures than those who merely ‘study’ them.