Active camouflage the surface, so when marine animals are seen from below, they appear darker than the background. Some species of cephalopod, such as the eye-flash squid and the firefly squid, produce light in photophores on their undersides to match the background. Bioluminescence is common among marine animals, so counterillumination may be widespread, though light has other functions, including attracting prey and signalling. Color change permits camouflage against different backgrounds. Many cephalopods including octopuses, cuttlefish, and squids, and some terrestrial amphibians and reptiles including chameleons and anoles can rapidly change color and pattern, though the major reasons for this include signalling, not
Military camouflage combined to expand the field of fire, and camouflage was widely used to decrease the danger of being targeted or to enable surprise. As such, military camouflage is a form of military deception. Camouflage was first practiced in simple form in the mid 18th century by jäger- or rifle units. Their tasks required them to be inconspicuous, and they were issued green and later other drab colour uniforms. With the advent of longer range and more accurate weapons, especially the repeating rifle, camouflage was adopted for the uniforms of all armies, spreading to most forms of military equipment including ships