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 unit, the first of its kind in any army. He also invented painted canvas netting to hide machine gun positions, and this was quickly taken up for hiding equipment and gun positions from 1917, 7 million square yards being used by the end of the war. The First World War also saw the birth of aerial warfare, and with it the need not only to conceal positions and vehicles from being spotted from the air, but also the need to camouflage the aircraft themselves. In 1917, Germany started using a lozenge camouflage covering Central Powers aircraft, possibly the earliest printed