Very cute and so interesting.
First thing that came to mind was, "How do kittens learn to purr in the first place?" The second thing was, "Did the kittens teach the squirrel how to do it? And what language did they use?" I'm not aware of any other animals purring.
Feeding is an automatic, instinctive impulse, but the purring is reallly strange and puzzling.
Thanks for posting.