Marsupials live in forests, plains, and deserts. They are found in the Americas, Australia, New Guinea, and some neighboring islands. They include kangaroos, koalas, wallabies, wombats, bandicoots, and opossums. Kangaroos are the largest marsupials - - a male red kangaroo can reach 6' high. Shrew-like ningauis are the smallest - - some of the latter weigh less than 1/10 ounce (2.8 grams).