When I was an undergraduate, there were always plenty of squirrels around. I especially liked when the landscapers put down a carpet of feltish, green fertilizer in the early spring. It made the little critters go bonkers. The computer scientists, of course, had their own fun with them: they went squirrel fishing.

As for imagination, Robert Mitchell edited a book called Pretending and imagination in animals and children in 2002 that might offer some answers. From what he wrote in the first chapter, I’m led to believe that people have observed what could be construed as imagintion in non-human primates. Part III of the book is dedicated to the details, but I haven’t made it there yet.