Crypsis

Reduction in detection through resemblance to the visual or other sensory background. It is distinct from recognition as a defended organism after detection.

Camouflage is concealment that reduces the chance that an observer detects or recognizes an organism. Crypsis can work through resemblance to the background; other patterns can disrupt the apparent outline of a body. Their effectiveness depends on the observer's sensory system, viewing conditions and animal behaviour.

A useful test measures detection or attack by the relevant predator against several backgrounds. A colour match judged by a human does not establish the same match for an observer with different colour vision. Camouflage and resemblance to a defended model in Batesian mimicry therefore require different explanations.