This chapter first focuses on the ethics of animal models and then discusses the formal requirements general to any experimental model and the specific requirements for models of hydrocephalus. It also discusses the recent and current research areas in experimental hydrocephalus. Ethical standards for experimental studies involving animals are legally set by laws and regulations. Animal models resemble human disease by conditions which are genetically determined, naturally acquired, or induced by the investigator. Shunted animal models provide a unique potential for insight into questions concerning the destructive effects of hydrocephalus on the brain and its development, as it is rarely possible to obtain brain tissue from humans with hydrocephalus. Most of the hydrocephalus animal models are neonatal or juvenile animals and the majority of research is thus directed at congenital or pediatric hydrocephalus.