It's very difficult to tell which is the smartest animal - or whether an animal is intelligent or not - because intelligence is a broad concept and there are ma

It's very difficult to tell which is the smartest animal - or whether an animal is intelligent or not - because intelligence is a broad concept and there are many kinds of intelligence. If you're interested in this topic a good book is "Are We Smart Enough to Know How Smart Animals Are?", by Frans de Waal.