Female kangaroos, like the females of other marsupials, have special abdominal pouches. The newly born young, commonly called a joey, finds its way into the pouch unassisted by the mother. The joey emerges permanently at from 6 to 10 months, and then stays with its mother, continuing to suckle by placing its head in her pouch, usually until it is 12 to 18 months old. The best-known and largest species of kangaroo are the giant, or great gray, kangaroo and the red, or woolly, kangaroo. Another large species, the wallaroo, is somewhat stouter.
Large kangaroos are terrestrial grazing animals that subsist chiefly on vegetation.
Sheep ranchers have claimed that the animals damage grazing lands, but such overgrazing can sometimes be attributed to the sheep themselves. Wallabies Kangaroos of smaller size, commonly called wallabies, are usually brighter in color than the large species. The rednecked wallaby inhabits thickets, whereas the rock wallabies live in crevices in rocks. The rock wallabies are chiefly nocturnal. The only arboreal kangaroos are the small tree kangaroos, whose front legs are almost as long as their hind legs.