Some test fish learned how to how to get food pellets but the difficulty, as so often, lies with interpretation.
The other day, walking down a tree-lined street, we were startled by a sudden crash and scramble at our feet.
The smartest of invertebrates, the octopus, once again prompts us to rethink what we believe to be the origin of intelligence.
If I gave you 15 seconds you could come up with a pat evolutionary just-so story to account for this, speculating on what reproductive advantage it serves.
An international team reasoned there had to be a purpose for sleep. In one of the largest datasets ever collected, they believe they found two functions.