Quick facts
- Common species
- House mouse (Mus musculus); wood mice also come indoors in autumn
- Body length
- About 7 to 10 cm, plus a tail of similar length
- Droppings
- Thin, pointed, about 3 to 8 mm long; a mouse leaves dozens a day
- Gap they can use
- About 6 mm, roughly the width of a pen
- Breeding
- Females can breed from a few weeks old and have several litters a year
How to identify mice
House mice are small, light brown to grey rodents with large ears, pointed noses and a long, thin tail. They are curious and nibble in many places, rather than eating a whole meal in one go, which is why you often find several chewed packets rather than one empty one.
A wood mouse (also called a field mouse) has larger eyes, longer hind legs and a pale belly. It usually lives outdoors but may come into garages, sheds and houses as the weather turns cold. Either species can be a problem once indoors.
Signs of mice in your home
- Small droppings in kitchen cupboards, behind appliances, along skirting boards and in lofts
- Chewed food packaging, with small, neat holes in cereals, bread, rice and pet food
- Scratching, rustling or squeaking in walls, ceilings, floor voids or under kitchen units
- Shredded paper, fabric or insulation used for nests
- Greasy smears or dark rub marks along walls
- A stale, ammonia-like smell in enclosed areas
- Gnawed wires, skirting boards or cardboard
Risks and damage
Mice contaminate food with urine and droppings and can spread bacteria such as salmonella. Their constant gnawing can damage cables, insulation and woodwork, and chewed wiring is a fire risk. Mouse allergens can also trigger asthma and allergies in some people.
Why mice come into properties
Mice come indoors mainly for warmth, food and shelter, which is why activity rises when it turns cold. Older properties with settled brickwork, gaps around pipes, ill-fitting doors and shared walls give mice many routes, and one infested home in a terrace can easily pass mice to neighbours.
How to prevent mice
- Seal gaps around pipes, cables, meter boxes and air bricks using wire wool and cement, metal mesh or rodent-proof filler
- Fit brush strips to the bottom of external doors and repair damaged door frames
- Store dry food, pet food and baking ingredients in glass, metal or hard plastic containers
- Clean up crumbs, move bins out of the kitchen overnight and keep floors clear of food
- Reduce clutter in lofts, garages and under stairs where mice can nest
- Trim vegetation and remove ivy that touches walls and gives easy access to the roof
Professional mouse control by Southwark Pests
Effective mouse control follows the same logic as rat control. A technician locates the entry points and activity, then uses traps and, where appropriate, bait in secure stations, followed by proofing and monitoring. Because mice nibble and wander, they can ignore bait if there is a lot of other food, so cleaning up food sources is part of the treatment.
Ultrasonic repellents are widely sold, but evidence that they solve an established infestation is weak. Cats do not reliably clear mice either. Dealing with how they get in and removing what they eat is the dependable approach.
When to call a professional
Call a professional if you see mice more than once, if you find droppings in food areas, if you hear noises at night, or if a previous treatment did not work. If you rent, report it to your landlord or agent in writing.
Mouse control across Southwark and London
Mice are the pest we are called about most in South London flats and terraces. They travel through shared floor voids, service ducts and pipe boxing, so one flat's problem is often a whole block's problem. 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
Mouse control: questions and answers
What attracts mice into my house?
Warmth, food and shelter. Crumbs, open food, pet bowls, cluttered storage and tiny gaps around pipes or doors all help mice settle.
How many mice are there if I see one?
If you see a mouse in daylight or more than one at a time, the population is usually larger than you think. Mice are nocturnal, so seeing one often means a nest is nearby.
Can mice climb walls and get into upstairs rooms?
Yes. Mice climb rough surfaces, pipes and cables, and travel inside wall cavities, so they can reach upper floors and lofts.
Is it safe to use humane traps?
Live-catch traps can work but must be checked frequently, and a mouse released nearby usually returns. Technicians weigh up humane options against the speed and certainty of the result.
How do I clean up after mice?
Ventilate the room, wear gloves, and avoid sweeping or hoovering dry droppings, which can put dust in the air. Dampen droppings with disinfectant, wipe them up with disposable cloths and wash your hands thoroughly.
How quickly can mice multiply?
Very quickly. A single pair can produce many young in a year, so acting early makes treatment simpler.
Related pages
This page is general information, last reviewed on 19 October 2026. It is not a substitute for an on-site inspection.