Final answer:
Migration is the relatively long-distance movement of animals from one area to another due to instinct.
Step-by-step explanation:
Migration is the relatively long-distance movement of animals from one area to another due to instinct. It is an evolved, adapted response to variation in resource availability, and it is a common phenomenon found in all major groups of animals.
For example, birds fly south for the winter to get to warmer climates with sufficient food, and salmon migrate to their spawning grounds. Migration is most common in birds, fish, and insects. It is triggered by changes in the environment, such as shorter days in the fall.