There are three species of kangaroo:
Kangaroos have large powerful hind legs, large feet designed for leaping, a long muscular tail for balance, and a small head. Kangaroos are herbivores, feeding on grass and roots, and they chew cud. All species are nocturnal and crepuscular, usually spending the days idling quietly and the cool evenings, nights and mornings moving about and feeding, typically in groups called mobs.
In addition, there are over 40 smaller macropods that are closely allied to the kangaroos:
Unlike many of the smaller macropod species, the large red and grey kangaroos have fared well since European settlement reduced dingo numbers, created vast grasslands intended for sheep and cattle, and added stock watering points in arid areas.
In some areas, kangaroos are culled by professional hunters, and the meat (which is tasty, tender, and low in fat) and hides are sold. Some conservationists argue that selective hunting practices (targeting young adult males) has put the population at risk, but there is no evidence of a decline in numbers. Some activists have undertaken campaigns to prevent the culling or farming of kangaroos, presumably misunderstanding the differences between kangaroos (which are not at all threatened) and other macropods, several of which are in considerable danger of extinction.
The word kangaroo is said to derive from the Guugu Yimidhirr[?] (an Australian Aboriginal language) word gangurru, referring to a particular species of kangaroo. The belief that it means "I don't understand" is a popular myth that is also applied to any number of other Aboriginal-sounding Australian words. Male kangaroos are called bucks, boomers or jacks; females are does, flyers, or jills and the young are joeys. The collective noun for kangaroos is a mob.
Kangaroos are popularly known as, along with koalas, the signature animals of Australia. As such they are common subject of toys and souveniers of the continent. The animal is also included in the Austrailian coat of arms