All animals, from ants to elephants, make decisions. And nature's critters continuously surprise humans with their thinking abilities.
Of course, it's hard to make a definitive ranking since measuring animal intelligence is problematic. Brain size, vocabulary, tool use, and social learning are common metrics of animal smarts, although it's difficult to compare between species since most intelligence tests or tasks are designed for a specific animals.
Animals evolve certain kinds of cognitive abilities to deal with pressures in their natural habitat, said Virginia Morell, author of "Animal Wise." Chimpanzees, for example, can make tools to hunt. Dogs may not use tools, but it doesn't make them less bright. They're just good at other things.  
We also tend to underestimate the brainpower of animals by relying too much on intelligence tests based around what humans are capable of. Right now, most people perceive speech as the main thing that separates humans from other animals, "but it's clear that parrots, dolphins, whales, and elephants have many more parts of language than we've recognized," Morell said to Business Insider.
And there are a lot of unknowns. We understand that comparing brain to body size is one way to measure intelligence, but "scientists aren't sure if that means you need a large brain, or just the ability to pack in a lot of neurons," said Morell.
The good news is "we're getting a better idea of how animals think and experience the world," Morrell said. "They aren't just roaming around feeling nothing. We know they do things with intentions, they have places to go, things to do, and they can never relax. Our sense of superiority is highly misplaced."
Here are a few animals that have surprised humans with their thinking abilities.

Chimpanzees are better than humans in some memory tasks



Our closest living relative is, unsurprisingly, not a fool. Primatologist Fras de Waal, of Emory University, crowned a young chimpanzee, named Ayumu, as number one on his list of "10 Animal Noble Prize for Overall Smartness" for outperforming humans at a memory task. Ayumu remembered the correct order of a series of numbers when they appeared at random for just 210 milliseconds on a touchscreen monitor — crushing human kids in the same task.
Chimpanzees are also known for their tool-making skills (De Waal notes that chimps have been seen fashioning spears out of sticks) and for learning how to communicate using sign language.
Goats recently amazed scientists by quickly solving a "mechanical puzzle" that caused a box to open, delivering a piece of fruit.
The goats also remembered the task after 10, suggesting they have "excellent long-term memory," co-author Dr Elodie Briefer, at ETH Zurich, said in a statement

 Elephants can work together