Penguins are flightless birds which live south of the Equator. As their legs are short, they 1USUAL stand upright and walk when they are on land. When they find it 2NEED to travel at greater speed, they often drop on to their stomachs and slide along. But it is at sea, 3SPECIAL when diving, that penguins really move fast, the 4WEIGH of their streamlined bodies allowing them to reach a 5DEEP of up to 265 metres in some cases. The sixteen species of penguin tend to look rather 6LIKE with black or dark blue backs and white fronts. But 7VARY in size and head patterns allow them to be 8IDENTIFY. The fact that a number of species spend their whole life in Antarctica where there is little protection from the world’s least welcoming weather conditions, makes their continued survival one of the wonders of nature.