I used sentient because it is used, to my knowledge, when referring to a creature which can use free will to determine actions, not just act on instinct or follow commands.
I've seen video of a Crow solving a problem with no prior training. It simply figured out what to do on it's own with no help. That proves me wrong in differentiating between humans and animals by using the word sentient and how I understood it.
To be clear:
The whale is governed by instinct with limited problem solving intelligence. It will work out how to evade danger when threatened, but doesn't appreciate art or study mathematics. Can figure out how to get to difficult prey, but will open wide it's mouth and move forward rather than learn manners and what flavors go best together.
The crow solving a problem is demonstrating Sapience. A bird flying off when it hears a loud noise or sudden movement is displaying Sentience. Same thing with a cockroach fleeing a bright light for the darkness.