The brown rat, sewer rat, Norway rat, (Rattus norvegicus) is best known as the common rat. One of the largest muroids. It has a body length of about 25 cm and a similar tail length. As adult, it weighs about 350g.

The brown rat is usually found where people live, especially in urban areas. It is nocturnal, omnivore and has opportunist tendencies, particularly feeds on waste released in sewers, that’s where the name “sewer rat” comes from.