Despite being so large and powerful, gorillas are gentle vegetarians. They spend most of their day walking slowly through the forest, pulling up roots, peeling bark, picking fruit and eating leaves. A full-grown gorilla can eat up to 30 kilograms of plants in a single day - the weight of a big suitcase full of food.
Gorilla families are led by a silverback male. He decides where the group travels each day, settles arguments and keeps everyone safe. The family also includes females, young gorillas and sometimes another young male who is still learning. Baby gorillas cling to their mother's back just as a human baby might be carried, and they stay with their mothers for several years.
Gorillas make a new sleeping nest every single evening. They bend branches and pile up leaves to create a soft platform in the trees or on the ground. Each morning they leave the nest and build a brand-new one the next night. Scientists sometimes count abandoned nests to work out how many gorillas are living in a particular part of the forest.
Gorillas share about 98.3 percent of their DNA with humans - more than any other animal except chimpanzees. Because of this close relationship, researchers who study gorillas learn a great deal about how early humans might have lived and communicated.