Humans aren't the only intelligent creatures on Earth. Research proves that animals are much smarter than most people realize. Many primates and birds are able to use tools, and plenty of mammals show advanced cognitive abilities. Even tiny insects can solve seemingly complex problems by working together.

1 of 10 Ravens Ravens may be creepy, but they sure are smart. DickDaniels / Wikimedia Commons / CC BY 3.0 Ravens are more than just the subject of dark themes by writer Edgar Allan Poe. They are also extremely resourceful animals that have been known to multi-task. Researchers from Canada and Scotland have shown that ravens use logic to understand their surroundings in a way that may 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.

2 of 10 Dolphins Dolphins have one of the largest brains in the animal kingdom. Georgette Douwma / Getty Images Dolphins are well-documented as intelligent animals. They can recognize themselves in a mirror and communicate with each other. Their large brain is structured for awareness and emotion, and dolphin brains are even more structurally complex than those of humans. According to Emory University dolphin expert Lori Marino, dolphins have larger brains than any other animal relative to the size of their bodies. Only humans have brains that are bigger.

3 of 10 Rats Rats are much smarter than we humans often given them credit for. sandra standbridge / Getty Images Perceived as purveyors of disease, rats have earned a bad reputation, but they are highly intelligent creatures. 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. However, certain rats are better at solving mazes than others, implying that there is a range of intelligence among the rodents.

4 of 10 Pigs Pigs are smart enough to outwit friends for food and can learn to perform various tricks. janecat / Shutterstock Pigs may be the smartest domestic animals in the world. Researchers have found that domestic pigs can 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.

5 of 10 Bonobos Like some other chimps and apes, bonobos are capable of learning human sign languages to express themselves. Psych USD / Wikimedia Commons / CC BY 3.0 The bonobo is a close cousin to the common chimpanzee, another famously intelligent animal. Extremely endangered, the bonobo is found only in central Africa. Like other great apes, bonobos 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. Furthermore, Kanzi can cook his own food and even outperformed a human toddler during a study of cognitive ability when he was only eight years old.

6 of 10 Ducks Ducklings imprint on their mothers, which may reveal advanced cognitive abilities. Ewais / Shutterstock 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 has only been seen in primates, crows, and parrots before, indicating that ducks may be smarter than originally thought.

7 of 10 Elephants The old saying "elephants never forget" may have some truth to it. These massive beasts sure are smart. Johan W. Elzenga / Shutterstock Elephants have a reputation for smarts. They 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." Elephants can recognize members of their herd even after being separated from them for years and can remember the locations of old water sources if their current home experiences a drought. However, their 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 entire banana trees unnoticed.

8 of 10 Cows Cows are not only smart animals; they're also very emotional. 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 emotions like fear and anxiety and also have excellent memories. Cows even develop their own social circles, becoming friends with the cows that treated them nicely and avoiding those that didn'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.

9 of 10 Bees Bees are smartest in groups, relying on swarm intelligence to get things done. Martin Ruegner / Getty Images 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 group of bees 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.