Known for their massive size but not often their massive intellect whales often use complex sounds to communicate with each other and coordinate their activities among the group very effectively. They are also formidable problem solvers.
Although their famous ability to talk is pure mimicry as most people know parrots have excellent memories and like many others on this list are capable of solving relatively complex problems.
When it comes to body mass to brain ratio, it is a scientific fact that Bottlenose dolphins have among the largest brains in the animal kingdom. Characterized by their advanced communication skills, they have also been considered to be self aware with the ability to recognize themselves in a mirror.
According to research, a middle aged pig can be as smart as a three year old human being and they know how to adapt to complex environmental situations because they have the ability to learn new skills easily.
Aside from the fact that chimpanzees look like humans, these animals also have the capacity in some ways to think like humans. They can manipulate their environment and utilize tools in order to help the community accomplish certain tasks. By and large they are often considered to be the smartest primate and therefore one of the smartest animals in the world.