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.
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.