The most common kinds of camouflage make one thing appear to be two, two things one, and so on. The occurrence of camouflage predates human history, in the sense that abundant examples exist of concealment and deception in nature. Some plants are often mistaken for stones, some birds have feathers that look like bark, and some insects resemble twigs (called mimicry). There are also natural textures that closely match their surroundings (called blending or crypsis), or forms that are so visually broken that they defy recognition (disruption) (see Figure 1; see also color insert, Figure 13). This entry describes natural camouflage, military applications, Gestalt psychology and camouflage, and more recent developments.