Any Australian macropod not large enough for kangaroo classification is a Wallaby. Smaller and stockier built than kangaroos, they have large hind legs, big feet, and long, powerfully muscled tail, short front legs, relatively small head with long ears, teeth for grazing, and pouches for babies. Some are very small heavily timbered forest-dwellers; others are rough rocky terrain inhabitants. Wallabies are sparse on great semi-arid plains whereby larger leaner, more fleet-footed kangaroos are better adapted.