The koala is an arboreal (tree living) herbivorous marsupial native to Australia. Its closest living relatives are the wombats.
Koalas typically inhabit open Eucalyptus woodland, and the leaves of these trees make up most of their diet. Because this eucalypt diet has limited nutritional and caloric content, koalas are largely sedentary and sleep up to 20 hours a day. They are asocial animals, and bonding exists only between mothers and dependent offspring.