Obsessive Hoarding: Persistent difficulty discarding or parting with possessions, regardless of the value of these possessions. Epidemiological studies suggest that hoarding occurs in 2-5% of the population and can lead to substantial distress and disability, as well as serious public health consequences.Compulsive Behavior: The behavior of performing an act persistently and repetitively without it leading to reward or pleasure. The act is usually a small, circumscribed behavior, almost ritualistic, yet not pathologically disturbing. Examples of compulsive behavior include twirling of hair, checking something constantly, not wanting pennies in change, straightening tilted pictures, etc.Obsessive-Compulsive Disorder: An anxiety disorder characterized by recurrent, persistent obsessions or compulsions. Obsessions are the intrusive ideas, thoughts, or images that are experienced as senseless or repugnant. Compulsions are repetitive and seemingly purposeful behavior which the individual generally recognizes as senseless and from which the individual does not derive pleasure although it may provide a release from tension.Phodopus: A genus of hamsters characterized by small size, very short tail, and short, broad feet with hairy soles.Obsessive Behavior: Persistent, unwanted idea or impulse which is considered normal when it does not markedly interfere with mental processes or emotional adjustment.Bonding, Human-Pet: The emotional attachment of individuals to PETS.Social Work, Psychiatric: Use of all social work processes in the treatment of patients in a psychiatric or mental health setting.