Camouflage there is no background, the principal methods of camouflage are transparency, silvering, and countershading, while the ability to produce light is among other things used for counter-illumination on the undersides of cephalopods such as squid. Some animals, such as chameleons and octopuses, are capable of actively changing their skin pattern and colours, whether for camouflage or for signalling. It is possible that some plants use camouflage to evade being eaten by herbivores. Military camouflage was spurred by the increasing range and accuracy of firearms in the 19th century. In particular the replacement of the inaccurate musket with the rifle made
Underwater camouflage bottom-living fish such as the flounder can hide themselves effectively against a variety of backgrounds. Many cephalopods including octopus, cuttlefish, and squid similarly use colour change, in their case both for camouflage and signalling. For example, the big blue octopus, "Octopus cyanea", hunts during the day, and can match itself to the colours and textures of its surroundings, both to avoid predators and to enable it to approach prey. It can perfectly resemble a rock or a coral it is hiding beside. When necessary, in order to scare away a potential predator, it can display markings which resemble eyes. Like