Due to many ethical concerns and safety, many experimental trials that cannot be performed in humans are performed in rats. They were the first mammalian species to be domesticated for use in the laboratory and the predominant animal model of human disease. Since rats are mammals, the basic structure, organizational principles, physiologies, and functionings, etc are similar to humans and hence the experimental findings and drugs applicable in rats model can be translated with a higher degree of confidence in humans than other models like yeast, C. elegans, fruit flies, zebrafish, etc.