Behavior: any observable activity of a living animal. Innate behaviors are performed in reasonably complete form the first time an animal of the right age and motivational state encounters a particular stimulus. The capacity to make changes in behavior on the basis of experience is called learning. Habituation: a common form of simple learning defined as a decline in response to a repeated stimulus. Trial and error: in which the animals acquire new and appropriate responses to stimuli through experience. Operant conditioning: an animal learns to perform a behavior to receive an award to avoid punishment. Insight learning: sudden problem solving, something animals do. Ethology: the study of animal behavior imprinting: a form of learning in which an animal"s nervous system is rigidly programmed to learn a certain thing only during a certain period of development. Communication: the production of a signal by one organism that causes another organism to change its behavior in a way beneficial to both.