Elephants are exceptionally smart creatures. They have the largest brain of any land animal, and three times as many neurons as humans. While many of these neurons exist to control the elephant’s large and dexterous body, these creatures have demonstrated their impressive mental capabilities time and time again. Here, a few interesting findings about the intelligence of elephants.

1. THEY CAN IDENTIFY LANGUAGES.

Researchers at the University of Sussex in Brighton, UK have discovered that African elephants can distinguish differences in human gender, age, and ethnicity purely by the sound of someone’s voice. If the voice belongs to a person who is more likely to pose a threat, the elephants switch into defensive mode.

To test this, researchers found two Kenyan men from different ethnic groups, the Maasai and the Kamba. The Maasai have a history of killing wild elephants, while the Kamba do not. The researchers recorded the two men saying, “Look, look over there, a group of elephants is coming,” in their different languages, and played these recordings to elephant family groups at Amboseli National Park in Kenya. When the elephants heard the Maasai, they showed signs of fear, huddling together and moving away from the voice. But the same phrase spoken by a Kamba man evoked no reaction from the elephants. "The ability to distinguish between Maasai and Kamba men delivering the same phrase in their own language suggests that elephants can discriminate between different languages," said the study’s co-author Graeme Shannon, a visiting fellow in psychology at the University of Sussex.

What’s more, the same recordings made by women and children of either tribe left the elephants unfazed, suggesting they can not only distinguish between ethnic groups, but between age and gender as well, knowing that men are the most likely to pose a threat, especially Maasai men.

2. THEY CAN USE TOOLS.

In 2010, a 7-year-old Asian elephant named Kandula impressed researchers by utilizing tools from his surroundings to reach fruit that had been strategically placed just beyond his reach. After watching the fruit, tantalizingly, for a few days, Kandula had an "aha moment." He found a large plastic block, rolled it over, and stepped on it, propping himself up just far enough to reach the fruit with his trunk. While Kandula’s “aha moment” didn’t happen immediately, it stuck with him. He repeated the trick with other tools, and even figured out how to stack blocks to reach even higher.

Similarly, elephants have been known to use sticks to scratch themselves in areas they couldn’t otherwise reach, and fashion fly swatters out of branches or grass. Others have been observed digging a hole to reach drinking water, and then plugging the hole with a ball formed from chewed bark to prevent the water from evaporating, thus saving it for later use.

3. THEY UNDERSTAND HUMAN BODY LANGUAGE.

Researchers recently observed evidence that elephants might understand human pointing. They tested this by pointing at food hidden in one of two identical containers, and observing which container a group of captive African elephants approached. Without any previous training, the elephants picked the correct container almost 68 percent of the time. That’s only about 5 percent lower than how one-year-old human babies perform on similar tests. When researchers stood between the containers and did not point, the elephants approached them randomly.

4. THEY SHOW EMPATHY.

A recent study [PDF] observed Asian elephants comforting one another when distressed. The elephants in the study used both physical contact and vocal sounds as forms of comfort, stroking one another with their trunks and emitting small chirps. The study concluded this behavior is "best classified with similar consolation responses by apes, possibly based on convergent evolution of empathic capacities."

5. THEY MOURN THEIR DEAD.

It would be a stretch to say elephants, or any other animals, understand death in the same way humans do. But elephants have demonstrated fascinating reactions to the deaths of their kind, often displaying what appear to humans as symptoms of grief and mourning. They caress the bones of the dead with their trunks and will stand near the body of the deceased for hours. Sometimes they even try to bury the remains. They don't behave this way toward the remains of other animals. In this powerful photo, taken by John Chaney for National Geographic, a female elephant "very slowly and with much empathy wrapped her trunk around the deceased elephant’s tusk. She stayed in this position for several hours…"

6. THEY MIMIC HUMAN VOICES.

An Asian elephant named Koshik baffled researchers in 2012 when they realized he could say five words in Korean. "If you consider the huge size of the elephant and the long vocal tract and other anatomic differences—for example he has a trunk instead of lips... and a huge larynx—and he is really matching the voice pitch of his trainers, this is really remarkable," said Dr. Angela Stoeger, a lead author of a study about Koshik that appeared in Current Biology. While it is almost certain Koshik doesn’t comprehend the meaning of the words, the researchers believe he began mimicking sound as a way to bond with humans, which were his only form of social contact during his formative years.

7. THEY HAVE EXTRAORDINARY MEMORIES.

You knew this one, but let’s point to some specific examples. Elephants can remember routes to watering holes over incredibly long stretches of time and space. This is necessary for elephants that live in the desert where water is scarce. Research also shows that elephants often form close bonds with companions, and can recognize them even after long periods of separation. Dr. Shermin de Silva, now director of the Uda Walawe Elephant Research Project in Sri Lanka, said in 2011 that “Elephants are able to track one another over large distances by calling to each other and using their sense of smell … Our work shows that they are able to recognize their friends and renew these bonds even after being apart for a long time." In 1999, two elephants named Shirley and Jenny, once companions in a circus, reunited at The Elephant Sanctuary in Tennessee after more than 20 years apart. Their immediate bonding can be seen in the video above, shot during their reunion.