The Black Rat (Rattus rattus) is usually smaller and lighter in build than the brown rat, with a longer tail compared with its body size and it also has a more pointed nose and smaller ears.
The black rat was the only rat in England until the 18th century, when it was ousted by its aggressive cousin, the brown rat.
The Brown Rat (Rattus norvegicus) tends to have smaller ears and eyes, and a blunter nose. The age of the rat can however sometimes lead to confusion when identifying the type of rat, with the young of both species tending to have larger eyes and ears proportionally.
The Brown Rat is incredibly adaptable and will live anywhere where there is access to food, water and shelter. Brown Rats are omnivorous and will eat just about anything from fruit and seeds to human food waste, insects, birds eggs and even small mammals. Commonly to be found around towns and cities. Brown rats are expert climbers, jumpers and swimmers. Originating from Asia these rats rapidly colonised with a pair of brown rats able to multiply to 200 in one year.
In domestic situations the Brown Rat will be found living in roof spaces, wall cavities or under floorboards. In gardens, they tend to burrow into grassy banks or are often to be found under sheds. Brown Rats can also be found living in sewer systems.
By comparison Black Rats are rare and are occasionally found in shipping ports. Although recent reports of the Black Rat being found in Cornwall have surfaced.