The brown rat is one of the best known and most common rats. It is a large variety of rat that has spread to all continents and is the most widespread mammal on the planet after humans. These rats live wherever humans live, especially in urban environments.
The brown rat Is most active at night, and is a good swimmer, but are poor climbers. However, they dig well, and often make extensive burrow systems.
The brown rat will eat just about anything but prefer cereals. Rats are known carriers of disease.