Animals shock us with the most bizarre appearances - some even look like they've been dressing up. But the weird and wonderful shapes and colours of nature are vital to the animals' lives. Sometimes they're disguised to help blend in, other times they are designed to stand out and show off. But whether it's a monkey in make-up or a salamander's toxic stripes, the weird and wonderful outfits enable the creature to thrive. The obvious place to start exploring animal outfits is the colourful parrots. The birds dazzling hues are not all caused by pigment, but more a clever reflection of the light. Bright, vibrant plumage is very attractive to a bird of the opposite sex - it demonstrates that the wearer is in good health, but surprisingly the main function of their bold markings is camouflage. There is an alternative to blending in. Some animals use colourful costumes to make themselves stand out. In the case of bold and bright tree frogs and salamanders, it's to warn would be attackers of toxins in their skins. Intimidation can also be used in the mating game, when a male wants to make himself bigger and more intimidating to his competitors. Many birds flaunt elaborate plumage to make themselves look more dramatic. The king of courting costume though is the peacock. With a two metre tail span, covered in colourful, eyelike markings, he's hard to ignore. But while some creature costumes are easy to explain, others remain a mystery. Animals dressing up might seem colourful to us, but perhaps it's not so strange - there is no species that enjoys putting on a costume as much as we do!