The goal is to give students a thorough understanding of abnormal behaviour in animals, and how these relate to evolutionary processes, domestication and animal production. Both external and internal risk factors are considered, as well development and biological (ethological and physiological) mechanisms and consequences to the individual animal. In addition, the use of abnormal behaviour as a measurement of animal welfare is considered.Abnormal behaviours such as stereotypies in general, tail biting in pigs, feather pecking in chicken and fur biting are considered.