Dinosaurs were mighty and powerful, but 4,000 species of mammal have outlived them. Mammals are the most diverse group of animals ever to live on earth. They can be as small as the 36mm pygmy shrew. Yet a blue whale can weigh more than 100 tonnes. How do they manage to colonise every part of the wrld? It is interesting to see.

The opening episode of The Life Of Mammals on TV tonight looks at special features that make a mammal: the ability of the animal to nurture their young on milk and regulate their own body temperature.

Do you know which mammal has the longest claws? Do you know the length of a blue whale? What are male grey kangaroos called? (Answers are printed below)