Many different species of rat exist. The most famous is the black rat. It's Latin name is Rattus Rattus. The brown rat or Norway rat is also very well known, its Latin name is Rattus norvegicus.
There are many different species of wild rats whereas all lab rats and pet rats come from Norway rats. The different varieties of pet rat such as Dumbo rats, hairless, platinum and tailless are all the same species. They are bred to exaggerate some of their physical characteristics.
Kangaroo rats are only distant relatives of the Norway rats. They are both rodents but this is where the similarity ends. They both belong to different families. Norway rats are more closely related to house mice then they are to kangaroo rats.
Kangaroo rats are fascinating. They are highly adapted to life in arid desert regions. They have very salty kidneys in the middle. This draws as much water as possible from their urine, making it very concentrated. They don't need to drink; they can get all the water they need from the seeds they eat.
Black rats and Norway rats are more closely related to each other. They are both in the genus Rattus. Amazingly though, there are currently 51 species within the genus.
Dr Toby Bateson for Hammer Technologies Ltd