Quick facts
- Common species
- Brown rat (Rattus norvegicus); the black rat is now rare in the UK
- Body length
- About 20 to 27 cm, plus a tail slightly shorter than the body
- Droppings
- Dark, capsule-shaped, roughly 12 to 18 mm long
- Gap they can use
- About 2 cm; far smaller than most people expect
- Active
- Mostly at night, so you often hear them before you see them
How to identify rats
Brown rats are heavy-bodied, grey-brown rodents with blunt noses, small ears and a scaly tail. They are larger than mice and a young rat is often mistaken for an adult mouse. The easiest clue is size: a rat's droppings are around the size of a large grain of rice or bigger, while a mouse's are closer to a grain of rice or smaller.
Rats are excellent climbers and swimmers. They travel along fixed routes beside walls and fences, and they use drains, pipes and cable runs to move between gardens and buildings. In cities they follow food, which is why bin stores, takeaway waste, bird feeders and compost heaps are such common starting points.
Signs of rats in your home
- Droppings along walls, under sinks, in lofts or near bins
- Gnaw marks on wood, plastic pipes, cables and food packaging
- Scratching, scurrying or gnawing noises from walls, floors, ceilings or lofts at night
- Greasy rub marks along skirting boards and wall edges where rats travel
- Burrows in soil, under sheds, decking, patios and beside drains
- Pet food or bird seed disappearing, or bins and compost heaps disturbed
- A strong, musty smell in enclosed spaces
Risks and damage
Rats can spread disease through their urine, droppings and bites, including salmonella and leptospirosis (Weil's disease). Serious illness is uncommon in the UK, but you should wash any cuts that touch contaminated water or surfaces and tell a doctor if you develop flu-like symptoms after rat contact. Rats also gnaw cables, which is a recognised fire risk, damage insulation and pipework, and contaminate food stores.
Why rats come into properties
Food, water and shelter. Open or damaged drains, uncovered food waste, overflowing bins, fallen bird seed, gaps around pipes, and cluttered gardens all help rats settle. Rats can also move into a property after nearby building work or drain repairs disturb an existing colony.
How to prevent rats
- Keep food waste in sealed, lidded bins and clear up spilled bird seed or pet food daily
- Fit non-return valves or intact covers to drains and repair damaged drain runs
- Seal gaps around pipes, vents and air bricks with rodent-proof materials such as wire wool and cement, or metal mesh
- Keep gardens tidy and avoid piles of wood, rubble or rubbish close to the house
- Do not compost cooked food, meat or fish in open compost heaps
- Store pet food and bird seed in sealed metal or hard plastic containers
Professional rat control by Southwark Pests
Professional rat control usually starts with an inspection to find where the rats are getting in, where they are nesting and what is feeding them. The treatment plan then combines blocking entry points (proofing), trapping or baiting with tamper-resistant bait boxes placed along their runs, and follow-up visits to check activity has stopped.
Rodenticides are strong products and are tightly regulated in the UK. Used properly by trained people they are safe around children and pets because bait is placed in secured boxes and monitored. Shop-bought poison scattered loosely is the opposite: it risks pets, wildlife and rats dying in walls where you cannot reach them. Proofing is what makes the result last, because baiting alone only deals with the rats already there.
When to call a professional
Call a professional if you see rats indoors, find droppings in a kitchen or loft, hear gnawing inside walls, or notice burrows near the building. In the UK, occupiers are expected to tell their local authority if rats or mice are present in substantial numbers, and landlords usually have a duty to deal with infestations in rented homes.
Rat control across Southwark and London
South London's mix of Victorian terraces, riverside developments, takeaways and old drain runs gives rats plenty of food and routes. We see rats in lofts in Peckham, under decking in Dulwich, in bin stores on Bermondsey estates and in drains all along the river. We cover South London, Central London (the City, the West End and Westminster), East London out to Stratford and Newham, and nearby parts of Kent, from our base at South Dock Marina in SE16. A standard visit is £90, and you can book online or call 020 8050 2022.
- Southwark
- Bermondsey
- Peckham
- Camberwell
- Rotherhithe
- Lambeth
- Brixton
- Lewisham
- Greenwich
- Bromley
- Bexley
- Kent
- Central London
- City of London
- Westminster
- East London
- Tower Hamlets
- Hackney
- Newham
- All areas
Rat control: questions and answers
How do I know if I have rats and not mice?
Check the droppings and the damage. Rat droppings are capsule-shaped and about 12 to 18 mm long; mouse droppings are thin, pointed and 3 to 8 mm. Rats leave larger gnaw marks and make heavier thumping or scratching noises.
Are rats dangerous to my family and pets?
Rats can carry diseases such as salmonella and leptospirosis, and they can contaminate food and surfaces. Keep children and pets away from rats and droppings, wash hands thoroughly, and get any bite or scratch looked at.
Will rats leave by themselves?
Usually not. If food, water and shelter remain, they stay and breed. Removing what attracts them helps, but an active infestation normally needs treatment and proofing.
How long does rat treatment take?
Many treatments run over several weeks with repeat visits, because rats are wary of new objects and bait takes time to work through a colony. Your technician can give you a realistic timeline after inspecting.
Can I use poison from a shop?
Be careful. Loose poison can harm pets, children and wildlife, and rats that die inside walls or lofts cause smells and fly problems. Professionals use secured bait boxes and trapping, and combine them with proofing.
Why do rats keep coming back?
Because entry points were never sealed or the food source remains. Proofing, drain repairs and good waste storage are what stop repeat infestations.
Do I have to report rats to the council?
Occupiers in England and Wales are expected to notify the local authority if rats or mice are present in substantial numbers. Councils can also act on neglected land or statutory nuisance problems. Check your own council's guidance.
Related pages
This page is general information, last reviewed on 19 October 2026. It is not a substitute for an on-site inspection.