Colours or structures that allow an animal to blend with its surroundings to avoid detection by other animals. Camouflage can take the form of matching the background colour, of countershading (darker on top, lighter below, to counteract natural shadows), or of irregular patterns that break up the outline of the animal's body. More elaborate camouflage involves closely resembling a feature of the natural environment, as with the stick insect; this is closely akin to mimicry . Camouflage is also important as a military technique, disguising either equipment, troops, or a position in order to conceal them from an enemy. In the military context, the three elements which primarily identify an object – shine, shape, and shadow – are altered to make the object difficult to identify. The most common technique is to use disruptive pattern painting, destroying shine and creating false shadows; this works effectively on ships, buildings, aircraft, and vehicles. Concealment of field positions is…