animals use the techniques of crypsis or camouflage, concealment, and mimicry, for avoiding detection. crypsis works by blending the structure with its background. the use of lichen flakes as an outer covering of nests by birds, as in the case of the paradise flycatcher ("terpsiphone paradisei") have been considered by some authors to be a case of crypsis through "branch-matching" and as a case of disruptive camouflage by the british ethologist, m. hansell, where the lichen flakes are thought to resemble small patches of light seen through as in the case of insubstantial objects of insufficient importance to receive a predator's interest.