Norway rats (Rattus norvegicus) are classified as pests. Here is detailed information about them:

– **Category**: Pest
– **Description**: Norway rats, also known as brown rats, sewer rats, or wharf rats, are large rodents that originated in northern China but have spread worldwide. They have a robust body, small eyes and ears, and a blunt snout. Their fur is coarse and typically brown or grey. Adults can weigh between 350 to 500 grams and measure about 40 cm in length, including the tail.
– **Impact**: Norway rats are considered major pests due to their ability to cause significant structural damage, contaminate food supplies, and spread diseases:
– **Property Damage**: They gnaw on various materials, including wood, plastic, and electrical wiring, which can lead to structural damage and increase the risk of electrical fires.
– **Contamination**: Norway rats contaminate food and food preparation surfaces with their droppings, urine, and fur. This contamination can lead to food spoilage and waste.
– **Disease Transmission**: They are vectors for several serious diseases, including leptospirosis, salmonellosis, rat-bite fever, and hantavirus. They can also carry parasites such as fleas, mites, and ticks, which can further spread diseases.
– **Impact on Agriculture**: Norway rats can cause significant damage to crops and stored grains, leading to economic losses in agriculture.

– **Control Methods**: Effective management of Norway rats involves a combination of preventive measures, trapping, and, in some cases, chemical control:
– **Preventive Measures**:
– **Exclusion**: Seal entry points such as cracks, gaps, and holes in walls, foundations, and around doors and windows to prevent rats from entering buildings.
– **Sanitation**: Keep areas clean and free of food debris, store food in sealed containers, and regularly dispose of garbage to reduce attractants.
– **Eliminate Nesting Sites**: Remove clutter and debris that can provide nesting sites for rats.
– **Trapping**:
– **Snap Traps**: Traditional spring-loaded traps that kill rats instantly.
– **Live Traps**: Humane traps that capture rats alive for relocation or humane euthanasia.
– **Glue Traps**: Sticky boards that trap rats when they walk over them (less humane and not recommended due to ethical concerns).
– **Chemical Control**:
– **Rodenticides**: Poison baits can be effective but should be used with caution due to potential risks to non-target animals, pets, and children. Rodenticides should be placed in tamper-resistant bait stations.
– **Professional Pest Control**: For severe infestations or when other methods are ineffective, professional pest control services can provide integrated pest management (IPM) solutions tailored to specific situations.

In summary, **Norway rats** are significant pests due to their ability to cause property damage, contaminate food supplies, and spread diseases. Effective management requires an integrated approach that combines preventive measures, trapping, and, if necessary, chemical control to reduce rat populations and prevent infestations.