Brown rat

Brown Rat

The Brown Rat (Rattus norvegicus), also known as the common rat, street rat, sewer rat, Hanover rat, Norway rat, Norwegian rat, or wharf rat, is one of the best known and most common rats.

Description

The brown rat is a large rodent that can weigh twice as much as a black rat and many times more than a house mouse. The length of the brown rat's body is typically between 20 and 25 cm, with a similar tail length.

Distribution and habitat

The brown rat is a true cosmopolitan species and is found throughout the world, particularly in urban environments. They prefer to live in close association with humans, and are therefore considered a commensal species.

Behavior

Brown rats are nocturnal, they have an excellent sense of balance and are superb climbers, being able to ascend vertical walls that are brick, stucco, or weathered wood. They are also capable of burrowing and often build complex systems of tunnels in the wild.

Diet

Brown rats are omnivores and commonly eat grains, fruits, vegetables, meat, and eggs. In urban environments, they are known to eat garbage and other food scraps.

Reproduction

Brown rats reach sexual maturity at about 5 weeks of age and can breed any time of the year, with peak breeding activity occurring in the spring and fall. The gestation period is only 21 days, and litters can number up to 14, although seven is common.

In culture

Throughout history, brown rats have been universally reviled as carriers of disease and are considered a pest species. However, they have also been kept as pets at various times, with the first record of domesticated brown rats being kept for their company dating back to the 20th century.

See also

• Black rat
• Rat
• Rodent
• Pest (organism)