The Norway Rat: Facts and Identification

Norway rats (Rattus norvegicus)

Norway rats, aka Rattus norvegicus, are city slickers found worldwide.

These adaptable rodents love living near humans, from sewers to attics, causing damage and spreading diseases. But, they’re not just pests; they have complex social lives too. 

Curious about managing these uninvited guests? Stick with us for the essentials on spotting, stopping, and saying goodbye to Norway rats.

Key Takeaways

  • The Norway rat, also known as Rattus norvegicus, is a versatile and common rodent in Louisiana.
  • They pose significant health risks as vectors for diseases like the Bubonic Plague and Leptospirosis, requiring effective rodent control and sanitation measures.
  • Eliminating Norway rat infestations involves securing food sources, limiting access to nesting materials, sealing entry points, and possibly using rodenticides.
  • Professional pest control is the best option to eliminate these rodents in severe cases and when DIY control methods fail.


In Louisiana, the Norway rats are a prevalent and adaptive rodent species. They are known by many names and play a notable role in various human habitats.

Overview of the Norway Rat

The Norway Rat, also known as the Norwegian rat or by its scientific name Rattus norvegicus, is a widely recognizable rodent known for its many names, such as:

  • Hanover rat
  • Brown rat
  • European rat
  • Sewer rat
  • Common rat

It is prevalent in regions like Louisiana, where it can significantly impact local ecosystems and human infrastructure.

Distinguishing Features

The Norway rat is easily distinguishable by its robust body, coarse fur, usually in shades of brown, and shorter tail. Here’s how it compares to other rat species.

FeatureDescription of Norway RatComparison to Similar Species
Fur ColorBrown with scattered black hairsBlack rat (Rattus rattus) has uniformly black fur
Tail LengthShorter than the body, semi-naked appearanceBlack rat has a longer, more uniform tail covering
EarsSmall and can barely cover the eyes if pulled downAustralian water rats have more prominent, more noticeable ears
SizeLarger and bulkier than most other Muridae family membersBlack rat and wharf rat are smaller and lighter

Life Cycle and Lifespan

Norway rats give birth to multiple litters annually, and they are notorious for hosting fleas, which have been associated with the spread of various diseases.

They exhibit sexual maturity within 2 to 5 months of birth, and their lifespans vary. However, they typically live up to a year or two in wild conditions.

Size and Senses

The Norway rats have a keen sense of smell, which is crucial for survival. It helps them locate food, avoid predators, and communicate with one another.

AspectNorway RatComparison
Body Length16 to 20 cm (6.3 to 7.9 inches)Similar to a teapot
Weight350 to 500 grams (12.3 to 17.6 ounces)Weighs about as much as a baseball
Sense of SmellHighly developedSuperior to humans, it aids in foraging and detecting predators


Norway rats are notorious for their high adaptability. They thrive in both cluttered urban environments and quieter rural settings.

They profoundly impact ecosystems and human habitats, specifically when they make their nests in sewers and basements.

Where Do Norway Rats Live?

The presence of these rodents signifies a robust and highly opportunistic species that has successfully spread from its origins in Northern China to other parts of the world. It includes:

  • North America
  • Europe
  • Asia

Their home range is typically close to a steady food source. It can vary widely depending on the area’s attraction factor.

AreaAttraction Factor
Urban Areas– High population density.
– Abundant waste and refuse as food sources.
Rural Areas– Access to natural food sources along river banks.
– Availability of crops in fields due to human agriculture.

The Norway Rat Diet

Norway rats are omnivores, not picky eaters. Their dietary flexibility allows them to forage for a wide variety of foods.

They can disturb homes and businesses by targeting readily available food stores.

What Attracts Norway Rats?

As homeowners, you should be aware of these attractants to prevent Norway rat infestations better and protect their living spaces.

  • Leftover food or poorly stored pantry items
  • Unsecured trash bins
  • Pet food bowls or leftover pet food


Norway rats play a critical role in epidemiology because they are vectors for several diseases that affect humans.

Public health authorities like the Centers for Disease Control and Prevention (CDC) provide information on rodent-borne diseases. Here are the common ones.

Disease or PathogenTransmission Method
Bubonic Plague (Yersinia pestis)Flea bites from infected rats
LeptospirosisContact with contaminated water
HantavirusInhalation of dust with rat urine/feces
Rat-Bite FeverBites or scratches from rats

You must implement effective rodent control strategies and maintain proper sanitation to lower the risk of contracting diseases from Norway rats.


You can identify a Norway rat infestation in Louisiana through various signs. These rodents are notorious for entering homes in search of food and shelter.

Here’s a closer look at common indicators of their presence:

DroppingsThey leave about 0.5-0.75 inches long pellet-shaped droppings.
Gnaw MarksTheir strong jaws leave visible chewing damage on food packaging, wood, or cables.
Grease MarksOily fur leaves dark grease marks along walls and baseboards as they follow the same paths.
Unusual NoisesScratching sounds or other vocalizations in walls or ceilings, especially at night, indicate they’re active.
NestsThey build nests from shredded materials like fabric or paper, usually hidden in dark locations.
Trail TracksRunways of footprints or tail marks may be visible in dusty environments or when using tracking powder.
Live or Dead RatsSightings of live or dead rats during the day can point to a large infestation.
Pet BehaviorPets may become excited or agitated if they detect Norway rats nearby.
Odd SmellsA musty odor may permeate the area, generally from their urine.


Eliminating Norway rats involves a multi-faceted approach. Here are improved strategies for effectively getting rid of these rats:

Eliminate Food Sources

To prevent future infestations, it’s crucial to cut off the Norway rats’ food supply:

  • Secure Food Storage: Store all human food in sturdy, sealed containers. Rats can easily chew through weak materials, so opt for metal or thick plastic bins.
  • Pet Food Management: Do not leave pet food out overnight. Store uneaten pet food properly and clean feeding areas regularly.
  • Prompt Cleanup: Address spills and crumbs immediately. Regularly address and dispose of dead animals that may attract them.

Limit Access to Nesting Materials

Norway rats look for comfortable materials to build their nests:

  • Vegetation Control: Trim tree branches and bushes to maintain at least a 3-foot clearance from your home’s foundation.
  • Secure Storage for Fabrics: Use durable, heavy-duty storage bins to prevent rats from accessing nesting materials.
  • Proper Disposal: Dispose of cardboard and other chewable materials promptly. Opt for recycling or secure disposal methods to minimize attraction.

Seal Entry Points

Securing your home against Norway rats requires careful attention to potential entry points:

  • Comprehensive Inspection: Thoroughly inspect your home for any cracks, holes, or gaps that rats could use to enter.
  • Use Durable Materials for Sealing: Seal all identified entry points with materials rats cannot chew through. Caulk smaller gaps to ensure a tight seal.
  • Trap Placement: After securing your home, strategically place live or snap traps around potential entry points or high-activity areas.

Use Rodenticide (Be Careful!)

While physical barriers and sanitation are critical first steps, rodenticides can be a potent addition to your pest control arsenal:

  • Safe Placement: If you use rodenticide, ensure it is placed in tamper-resistant bait stations to prevent non-target animals and children from accessing it.
  • Selecting the Right Formula: Consult a pest control professional to determine the most effective and appropriate type for your situation.


As American residents who notice signs of rat activity, you should consider taking action to control the rat population.

Effective control of Norway rats involves a strategic and multi-faceted approach to rat control and pest management.

DIY vs. Professional Pest Control

When facing a Norway rat infestation in Louisiana, you can choose DIY pest control methods or hire professional pest control services.

Each approach has its own set of advantages and disadvantages.

AspectDIY Pest ControlProfessional Pest Control
CostGenerally less expensive in the short term.Cost-effective in the long run.
ExpertiseLimited to the knowledge of the individual.They have specialized training and knowledge.
Time and EffortCan be time-consuming and require ongoing effort.Saves time as professionals handle the process.
RiskHigher risk of improper handling of poisons or traps.Lower risk due to proper training in handling hazardous materials.
EffectivenessVaried effectiveness, depending on the individual’s skill.Generally more effective due to advanced techniques.
Long-term SolutionsMay not address the root cause of the infestation.It includes a comprehensive plan to prevent re-infestations.


When Norway rats become unwelcome tenants in your home, consider seeking the pest control professional’s help.

Here are several considerations to determine if professional intervention is needed:

  1. Signs of a severe infestation warrant a call to the pros.
  2. Persistent pests suggest it’s time for expert strategies.
  3. Professionals know how to handle risks safely and effectively.
  4. Experts should step in if handling rodents is outside one’s comfort zone.

Wherever you’re in Louisiana, seeking expert help should be easy. For immediate intervention for a severe infestation, let Lajaunie’s rat control specialists tailor a solution that’s right for your home.

For more information about the areas we service, visit our location page