Brown Rat (Norway Rat)

How to Identify a Brown Rat

The brown rat is larger and heavier than a house mouse or roof rat. Knowing the key differences helps you understand what you are dealing with.

• Size: Body length around 25 to 30 cm including the head, with a tail that is shorter than the body.
• Fur colour: Brown or reddish grey on the back, with a whitish grey underside. Some individuals can look almost black.
• Ears: Small, close to the head, and not as prominent as a mouse.
• Snout: Blunt, compared with the pointed snout of a mouse.
• Tail: Scaly, fairly thick, and shorter than the combined head and body length.

House mice are much smaller, finer in build, with relatively large ears and a pointed snout. Roof rats, sometimes called black rats, are slimmer, have larger ears, and a tail that is longer than the body.

Behaviour and Nesting Habits

• Main UK species: The Norway or brown rat is the species that causes most rat problems in the UK.
• Breeding: Females can breed about every 21 days and typically have 4 to 6 young per litter, so numbers can increase quickly.
• Where they live: Common in towns and cities, but also present in rural areas. They are often found around drains, sewers, outbuildings, sheds, and gardens.
• In buildings: They usually enter at ground level or below, then move through cavity walls and can eventually reach lofts and roof spaces.
• Nesting sites: Behind walls, under floors, in crawl spaces, loft insulation, cluttered storage areas, banks of streams, ditches, and dense vegetation.

Brown rats are not picky about what they eat. They will feed on stored food, rubbish, pet food, and many non food materials they chew while exploring.

Rat Droppings and How to Tell Species Apart

Droppings give a strong clue about which rodent is in your property and where they are active. You often find them in kitchens, cupboards, pantries, lofts, and along regular run routes.

• House mouse droppings: About the size of a grain of rice, slender, rod shaped, with pointed ends.
• Roof rat droppings: Around 6 mm long, spindle shaped, with pointed ends. Larger than mouse droppings, but smaller than brown rat droppings.
• Brown rat droppings: The largest, around 12 to 15 mm long. Usually shiny dark brown or black, although the colour depends on diet.

Damage Caused by Brown Rats

Brown rats can cause extensive damage to both homes and commercial buildings.

• Chewed wiring: Gnawing on electrical cables can increase the risk of fire.
• Damaged pipes: Chewing through water pipes can lead to leaks and water damage.
• Insulation and structure: They shred insulation, damage plasterboard, wood trim, and other building materials.
• Stored items: Clothing, cardboard boxes, books, and packaging are often shredded for nesting.

Health Risks from Brown Rats

Brown rats are a significant health risk. Their droppings, urine, and parasites can carry diseases that affect people and pets.

• Leptospirosis (Weil’s disease)
• Salmonellosis and other forms of food poisoning
• Murine typhus

Contaminated food or surfaces, and contact with rat urine in water or soil, are common routes of infection. Proper cleaning and professional control are important to reduce these risks.

Brown Rat vs House Mouse at a Glance

• Ears: Brown rat has small ears; house mouse has large, prominent ears.
• Fur: Brown rat fur is coarse, red brown to grey brown; house mouse fur is smoother, dirty grey or brownish grey.
• Snout: Brown rat snout is blunt; house mouse snout is pointed.
• Tail: Brown rat tail is shorter than its head and body combined; house mouse tail is often similar in length to the head and body.

Professional Brown Rat Control

If you have seen a brown rat, there are likely more nearby. Because they breed quickly and can cause both damage and health problems, it is safer to use a professional pest control service rather than tackling the problem on your own.

Forest Of Dean Pest Control will carry out a detailed survey, identify entry points, nesting areas, and food sources, then use safe and effective control methods. You also receive clear advice on proofing and hygiene to reduce the chance of future infestations in your property.

Contact Forest Of Dean Pest Control today to arrange a brown rat inspection and treatment in the Forest of Dean area.