Ostriches, emus, rheas, cassowaries and kiwis walk or run everywhere. Flightless birds are often very large, but have very small wings, used only for balancing and display. As a group, they are sometimes called ratites, although scientists are not certain how closely related they are to each other. Emus are inquisitive birds. They feed on fruit and insects but are known to steal coins and keys.
Cassowaries are wary, aggressive birds, active mainly at night.
They are found in New Guinea and Australia. Ostriches are the world's largest birds, reaching almost 2.5m tall and weighing up to 150kg. Kiwis are found only in New Zealand. They are hen-sized and feed mainly at night on insects and berries. Adelie penguins are so well-adapted to the cold that they can breed even in the bitter chill and darkness of an Antarctic winter.