In his book Cosmos, Carl Sagan wrote, "Imagination will often carry us to worlds that never were. But without it we go nowhere."
In the photo above, Koko the gorilla plays with a doll, apparently pretending to nurse it. But can non-human animals really pretend? Do they have the ability to imagine? Can animals carry themselves to worlds that never were, as human children routinely do? These are the questions I explore in my latest piece at BBC Future:
An eight-year-old juvenile chimpanzee named Kakama trudged along a path among the forest trees, following his pregnant mother. A scientist sat silently at a distance, watching Kakama pick up a log and carry it with him for hours. At one point, Kakama made a nest and placed the log in it, as if it were a small chimpanzee. Months later, two field assistants observed the same thing: Kakama was playing with a similar log, which they labelled "Kakama's toy baby."
Image via Koko.org