The domesticated rat, although often called the Norway rat (rattus norvegicus), actually came from Asia Minor and colonized Europe in the early 18th century. They were called Norway rats because they arrived in large numbers on Norwegian shipping vessels. On their arrival, they quickly spread and drove out the native black rats (rattus rattus) because they were larger and more adaptable. Out of their success, the occupation of rat-catcher was born and England's royal rat catcher, Jack Black, is credited as the originator of the first domesticated rat. Jack Black raised and bred rats in captivity and eventually had many different varieties including albino, fawn, black, grey, and marked, which he sold as pets. Today many more varieties are available including all sorts of colors and markings. Since they have been bred to be friendly and docile, they make excellent pets.
There is much prejudice against rats because in many parts of the world wild rats remain a major pest and are responsible for the transmission of diseases and consuming large portions of the world's food harvest. However, rats are crucial to scientific research and have made many contributions to human health by serving as a model organism. They were the first mammalian species domesticated for research and almost all human genes linked with disease have counterparts in the rat.