They're known as gentle giants. Elephants, found across Africa and Asia, are the largest mammals on land. And their massive bodies — from their sensitive feet to their complicated brains — are perfectly attuned to these regions' savannas and forests.

Though elephants walk on their tip toes, they are still able to cover long distances. That is because they have wedge-like fat pads that give them flat feet. Hidden in those fat pads, are also large false toes called predigits which further give them support by spreading the load from the sole up the limbs.

Their feet have another surprising function: communication. Elephants can pick up on low frequency rumblings or stomping from up to 20 miles (about 32 kilometers) away. These sounds create seismic vibrations on the earth's surface that the animals can sense with their feet. Researchers believe those vibrations travel all the way up their ears via their skeletons. This skill allows elephants to detect danger from far away.

What language is this?

But the colossal mammals aren't only well versed in their own communication. A 2014 study found they can also distinguish between human languages — and whether the voice comes from a man, woman or child. This comes in especially handy when they gauge how much of a threat humans pose to them.

Researchers played different voice recordings to wild elephants in Amboseli National Park in Kenya to watch how defensive they got. Between recordings of Maasai men and Kamba men, the animals reacted more strongly to the sound of the Maasai, who had killed elephants on occasion. The herd also retreated less when it heard the sounds of Maasai women or young boys who generally don't threaten elephants.

An elephant never forgets

Their ability to distinguish languages is a testament to elephants' renowned memories. Not only do they have the largest brains of any land mammal, but they even have more pyramidal neurons than humans. These neurons are thought to be important for cognitive functions, meaning elephants might have more advanced memory skills than us. It is no surprise then that they can remember the shortest distance to watering holes, even if they are 31 miles (50 kilometers) away.

They also need these cognitive abilities to live in their complex societies. But traumatic experiences, like losing relatives to poachers or being separated from the herd, can hinder neurological development, making elephants aggressive and fearful. These types of disruptions also mean that younger elephants miss out on vital social information that adults would have passed down to them.

Elephants are especially endangered in Asia where their population has declined by at least 50% in the last three generations (about 75 years). That is mostly because humans continue to infringe on their habitat. But they are also under threat of poaching in parts of Africa.