In this article we'll pay attention to those smart animals who's intellect is largely disregarded. So, we'll skip chimps who are so evolved that there have been reports that one chimp, after being reintroduced to the wilderness, made a spear and started fishing with it. We'll also skip other well known smart animals like dolphins, dogs, cats and so on.
Pigs are more intelligent than both cats and dogs. They are also known as the most intelligent domesticated animals. Their brainpower is estimated to be on a level of a three-year-old child.