10 of the Smartest Animals on Earth

Humans might be the most intelligent creatures on Earth, but some other animals are catching up to us quickly. Research proves that animals like primates and birds are able to use tools, and plenty of mammals show advanced cognitive abilities like language comprehension and mathematical skills. Even tiny insects can solve seemingly complex problems by working together.

You've heard of IQ? Well, EQ—encephalization quotient—is the measure used to describe an animal's intelligence by comparing its brain to that of a creature of the same size. Humans have an EQ of about 7.5, whereas a possum has an EQ of 0.2. The mean EQ for mammals is 1. It is worth noting that some experts argue it's brain size overall, not EQ, that determines cognitive ability in nonhumans.

From dolphins to bees, pigs to rats, here are 10 of the smartest animals in the world.

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Ravens

Close-up of raven with blurred canyons in background — Norbert Kurzka Photography / Getty Images

Ravens are more than just the subject of dark, Poean themes. They are also extremely resourceful birds that have been known to multitask. Researchers from Canada and Scotland have shown that ravens use logic to understand their surroundings in a way that may even surpass the ability of the great apes.

When presented with food that could only be attained by completing a series of complicated tasks, the ravens figured out how to reach the treats on their own without assistance from the researchers.

The raven's EQ has been estimated at 2.49.

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Dolphins

Dolphins' smarts are well-documented. These cetaceans can recognize themselves in a mirror and communicate with each other. Their large brains are structured for awareness and emotion and are even more structurally complex than those of humans. According to researchers, dolphins have larger brains than any other nonhuman animal relative to the size of their bodies.

The EQ of dolphins is also the highest, apart from humans', at 5.3.

9 Mind-Boggling Dolphin Facts

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Rats

Wild brown rat eating seeds on the ground in foliage — sandra standbridge / Getty Images

Their poor reputation for being pests aside, rats are highly intelligent. Pet rats can be trained just like dogs and can learn how to fetch or roll over. Their ability to solve problems has also been documented by numerous scientific studies, such as those in which rats found their way through mazes with the reward of food.

Certain rats are better at solving mazes than others, though, implying that there is a range of intelligence among the rodents.

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Pigs

Pigs may be the smartest domestic animals in the world, even smarter than your family dog. Researchers have found that domestic swine use mirrors to find their food and will try to deceive other pigs so that they can "hog" more food.

Pigs also learn quickly and can do tricks ranging from jumping through hoops to playing video games with joysticks. Adults have an EQ of 0.38, but studies point out that the brain-to-body size ratio in pigs has been altered by the necessity of improved body weight in meat production.

8 Surprising Facts About Pigs

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Bonobos

The bonobo is a close cousin to the common chimpanzee, another famously intelligent animal. Its EQ has been estimated at 1.80 to 2.36 in various studies, both similar to—but not quite reaching the level of—chimps'.

Like other great apes, these primates can learn how to use sign language and symbols. After researchers taught a bonobo named Kanzi how to communicate with lexigrams on a keyboard, the ape taught himself some basic sign language just by watching videos of Koko the Gorilla. Kanzi, who now lives at a research center in Des Moines, Iowa, can cook his own food and has even outperformed a human toddler during a study of cognitive ability when he was only eight years old.

Extremely endangered, the bonobo is found only in central Africa.

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Ducks

Ducklings are known to imprint on their mothers, but how much does this reveal about their cognitive abilities? To find out, scientists at the University of Oxford studied how the ducklings managed to differentiate between imprinted beings and non-imprinted. They put ducklings in an enclosure and trailed two different pairs of objects around on strings, one pair of matching shapes (like two spheres) and one pair of non-matching shapes (like a cylinder and a cube). After the ducklings showed a tendency towards one of the sets, the researchers put the ducklings in a different enclosure with different matching and non-matching pairs.

The ducklings would follow after whichever set best resembled their original imprint. So, if they followed the two spheres in the first enclosure, they would follow a set of matching cubes in the second enclosure. The researchers explained that this tendency had been seen only in primates, crows, and parrots, indicating that ducks may be smarter than originally thought.

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Elephants

A mother elephant and her two children walking through savanna — Johan W. Elzenga / Shutterstock

Elephants have been observed using tools such as sticks to pick at ticks and palm fronds to swat at flies. They also have an excellent memory, hence the saying "elephants never forget." They can recognize members of their herd after years of separation and remember the locations of old water sources if their current home is in a drought.

However, elephants' intelligence may sometimes put them at odds with their human neighbors. As the Nature Institute points out, some farmers equip elephants with wooden bells to alert them if the animals have entered their banana groves, but young elephants have been observed stuffing their bells with mud so that the clappers cannot ring, allowing them to eat banana trees unnoticed.

13 Fascinating Facts About Elephants

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Cows

Cow with bell around its neck on alpine pasture — Westend61 / Getty Images

Cows may seem like placid animals merely concerned with chewing their cud, but as it turns out, they possess a rich and complex emotional life. They experience fear and anxiety and also have excellent memories. Cows even develop their own social circles, becoming friends with the cows that treat them nicely and avoiding those that don't.

One scientific study also revealed that when cows were rewarded for improving at a task, they were more excited than when they were given a treat regardless, indicating that cows are aware of their own learning improvement.

22 Things You Didn't Know About Cows

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Bees

Bees exhibit what experts call classic swarm intelligence. A single bee may not be smart in the classical sense, but a hive of bees can be. If a swarm needs to find a new nest, they work together to collect information and share their findings, ultimately voting on which location would best serve as their new home.

What happens when bees disagree? It turns out that they can hold a democratic "dance-off" to make a hive decision.

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Squirrels

Squirrel perched on log eating a nut — Sandra Standbridge / Getty Images

Squirrels are fast learners, according to a study from the University of Exeter, and they learn from their peers, especially when stealing food is involved. Furthermore, while squirrels are known to bury food in the fall in preparation for winter, they will sometimes only pretend to bury it to trick onlooking animals and protect their food supply.

Studies have found tree squirrels to have a higher EQ than ground squirrels and gray squirrels to be smarter than red squirrels.

22 Things You May Not Know About Squirrels

What Characteristics Do Intelligent Animals Share?

There are so many ways in which an animal can be "smart." Some are good at language but have poor mathematical skills, and vice versa. Here are some of the ways nonhuman animals exhibit intelligence.

Self-awareness: The "mirror test" has long been used to gauge animal intelligence. If an animal recognizes itself in a mirror—as we know apes, elephants, dolphins, magpies, and some other species can do—that indicates a heightened level of self-awareness.
Problem solving: Tool use is an impressive testament to an animal's problem-solving skills. In addition to elephants, dolphins also use tools when they carry marine sponges to stir up sand and uncover prey.
Language comprehension: Though they don't use the same language as humans, animals do communicate with each other via vocalizations and sign language. Birds, primates, bats, cetaceans, and even insects do this.
Altruism: Altruism is apparent in species with complex social structures, like honey bees. Worker bees, for example, forgo their own reproduction to help rear their siblings.