Compulsive behavior may then occur in situations where the pet is minimally aroused. Compulsive behaviors are often derived from normal behavior patterns but appear to be abnormal because they are excessive, exceedingly intense, or performed out of context. Although some compulsive disorders are repetitive and may therefore be referred to as stereotypic (wool sucking, pacing, tail chasing), other compulsive disorders such as freezing or staring are not truly repetitive.