Sir David Attenborough takes a look at the zebra's stripes and the wings of the butterfly in the final episode of his series, David Attenborough's Natural Curiosities.
The zebra’s stripes have intrigued scientists since the animal's discovery on the African plains in the 18th Century by European explorers.
Even today no one knows for sure exactly why the zebra has a strange stripy coat.
Butterflies are one group of creatures that have evolved colourful patterns of seemingly infinite variety and beauty.
The Natural History Museum now houses over 3 million butterfly specimens from every corner of the world.
With modern tools we can only just begin to really understand the mechanisms that lie behind their splendid patterns.