This issue of Veterinary Clinics: Exotic Animal Practice, guest edited by Dr. Marion R. Desmarchelier, focuses on Behavior. This is one of three issues each year selected by the series consulting editor, Dr. Jörg Mayer. Articles in this issue include, but are not limited to: Behavior modifications for the exotic pet practitioner, Psychopharmacology for the exotic pet practitioner, Ferret behavior medicine, Rabbit behavior medicine, Pot-bellied pig behavior medicine, Abnormal repetitive behaviors and self-mutilations in small mammals, Medical causes of feather damaging behavior, Avian behavior consultation for the exotic pet practitioner, Bird of Prey behavior for the avian practitioner, Clinical reptile behavior, Amphibian behavior for the exotic pet practitioner, Fish behavior for the exotic pet practitioner, Invertebrate behavior for the exotic pet practitioner, and Non-human primate clinical behavior.