Instinctive behavior

(zoology) Any species-typical pattern of responses not clearly acquired through training.

A relatively complex response pattern which is usually present in one or both sexes of a given species. These responses have a genetic basis, are essentially unlearned, and are generally adaptive.

Components of instrument landing system (ILS), and resulting signals used by the pilot. (Federal Aviation Administration)

Instinctive behavior occurs when an animal has a particular internal state while it is in the presence of a specific external stimulation called a releaser or a sign stimulus. Neither the internal state nor the external stimulus alone is adequate for the elicitation of the response. Many animals show particular instinctive behaviors only during the mating season, when hormonal changes associated with sexual behavior sensitize specific portions of the central nervous system, which will then be active in the presence of the releaser. The external stimulus may be relatively simple or incredibly complex.

Within limits, the instinctive behaviors can be modified by learning. There is evidence, for example, that some predators learn to attack their prey at the back of the neck because when held in that position the prey cannot counterattack. See also Migratory behavior; Reproductive behavior.