This is the first article with reference to the theme.
Camouflage is a set of methods of concealment that allows otherwise visible animals, military vehicles, or other objects to remain unnoticed by blending with their environment or by resembling something else. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly. Camouflage is a form of visual deception; the term probably comes from camouflet, a French term meaning smoke blown in someone's face as a practical joke.
Animal coloration is the general appearance of an animal resulting from the reflection or emission of light from its surfaces. The mechanisms for colour production in animals include pigments, chromatophores, structural coloration, and bioluminescence.
There are several separate reasons why animal coloration may evolve, including camouflage, enabling an animal to remain hidden from view, signalling to other animals, of the same or different species, diversion, physical protection, such as having pigments to protect against sunburn, and incidentally, such as having red blood because, as it happens, haem (needed to carry oxygen) is red. All of these can create striking natural patterns.
One of the pioneers of research into animal coloration, Edward Bagnall Poulton classified the forms of protective coloration in a way which is still helpful.
Protective resemblance is used by prey to avoid predation. It include special protective resemblance, now called mimesis, where the whole animal looks like some other object, for example when a caterpillar resembles a twig or a bird dropping. In general protective resemblance, now called crypsis, the animal's texture blends with the background, for example when a moth's colour and pattern blend in with tree bark.
Here some astonishing animals that blend with the background.