Deutsch: Wanderratte / Español: Rata noruega / Português: Rato-norueguês / Français: Rat surmulot / Italiano: Ratto norvegese

Rattus norvegicus, commonly known as the Norway rat, brown rat, or sewer rat, is a species of rodent often associated with urban environments but it has significant impacts on various ecosystems around the world. This species is renowned for its adaptability to different habitats and its ability to survive in close quarters with humans.


Rattus norvegicus is a robust, omnivorous rodent that has a worldwide distribution largely due to human activities. It originated in northern China and later spread to Europe and the Americas primarily through maritime activities. The Norway rat builds complex systems of burrows and is known for its excellent swimming abilities, which aid in its survival in sewers and its ability to colonize new areas.

In the environment, these rats are often considered pests due to their impact on human habitats and agriculture. They can damage crops, contaminate food supplies, and chew through materials like pipes and wires, causing fire hazards and infrastructure damage. Moreover, they are carriers of various diseases, which can affect both humans and wildlife, making them a significant public health concern.

Application Areas

The impact of Rattus norvegicus on the environment and its management includes:

  • Pest control: Efforts to manage rat populations in urban and rural settings through traps, poison, and habitat modification.
  • Public health campaigns: Measures to mitigate the health risks associated with rats, including the spread of diseases such as leptospirosis, hantavirus, and bubonic plague.
  • Biodiversity conservation: Strategies to protect native wildlife from predation and competition with rats, particularly on islands where native species are highly vulnerable to invasive rodents.

Well-Known Examples

Control and eradication campaigns against Rattus norvegicus have been implemented on various islands worldwide to protect native birds and other wildlife. For example, efforts on the Galápagos Islands involve extensive rat control programs to preserve unique endemic species that are threatened by rodent predation.

Treatment and Risks

While necessary for ecological and health reasons, rat control measures can have unintended environmental impacts, such as the poisoning of non-target species and the disturbance of ecosystems. Furthermore, the resilience and rapid reproduction rates of Norway rats often make eradication efforts challenging and costly.

Integrated pest management (IPM) approaches that combine biological, physical, and chemical control methods are considered more sustainable and effective in managing rat populations while minimizing ecological damage.

Similar Terms

  • Invasive species: Rattus norvegicus is often classified as an invasive species outside its native range, particularly on islands where it can cause significant ecological damage.
  • Synanthropic species: Species like the Norway rat that live near and benefit from an association with humans and human habitats.


Rattus norvegicus is a significant environmental concern due to its impacts on human health, agriculture, and biodiversity. Effective management of this species requires a careful balance of control measures to mitigate its negative effects while considering the broader ecological consequences.


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