For the material that is eaten by foraging by animals, see Forage.

Foraging theory is a branch of behavioral ecology that studies the foraging behavior of animals in response to the environment in which the animal lives. Foraging theory considers the foraging behavior of animals in reference to the payoff that an animal obtains from different foraging options. Foraging theory predicts that foraging options that deliver the highest payoff, should be favored by foraging animals because it will have the highest fitness payoff.