Chameleon turquoise, and purple. Chameleon skin has a superficial layer which contains pigments, and under the layer are cells with guanine crystals. Chameleons change colour by changing the space between the guanine crystals, which changes the wavelength of light reflected off the crystals which changes the colour of the skin. Colour change in chameleons has functions in camouflage, but most commonly in social signaling and in reactions to temperature and other conditions. The relative importance of these functions varies with the circumstances, as well as the species. Colour change signals a chameleon's physiological condition and intentions to other chameleons. Chameleons tend
Self-decoration camouflage Self-decoration camouflage Self-decoration camouflage is a method of camouflage in which animals or soldiers select materials, sometimes living, from the environment and attach these to themselves for concealment. The method was described in 1889 by William Bateson, who observed "Stenorhynchus" decorator crabs. It was classified as "adventitious protection" by Edward Bagnall Poulton in 1890, and as "adventitious concealing coloration" or "adventitious resemblance" by Hugh Bamford Cott in 1940, who compared it to the way Australian aborigines stalked waterfowl, covering their faces with water lily leaves. Among animals, self-decoration is found in decorator crabs, some insects such as caddis flies and