According to this fascinating article:
HUMAN minds wander when they have nothing else to do. This is when people start to introspect, using a specific network of brain structures. The same network has now been identified in monkeys and rats, suggesting that “zoning out” might serve a key function in our survival. The findings raise questions over whether lower animals might also be capable of something akin to introspection.
The prospects of an introspective rat raises profound questions for consciousness and how it applies to the rest of creation. Or does it? The fact that similar networks exists in rats and primates does not automatically mean that their functionality is identical, as the article makes clear. But it certainly makes for interesting conjecture and opens up a plethora of avenues for further experimentation.