Household pests
Mice and rats: signs, risks and how to get rid of them
Mice and rats give themselves away through droppings, gnaw marks, grease smears and night-time scratching. They can carry disease, contaminate food and gnaw wiring, so a rodent problem is taken seriously. Blocking entry points and trapping can clear a small problem, but established infestations usually need a professional or council pest service.
- Also known as
- house mouse, Mus musculus, brown rat, Rattus norvegicus
- Easily confused with
- squirrels in lofts (larger, daytime activity), birds nesting in eaves
- How serious
- High: a health and property risk that breeds fast if ignored
- Typical cost
- Council treatment may be free or low cost; private rodent treatment commonly from around 95 to 250 pounds
How to identify mice and rats
Mice leave small, dark, rice-grain droppings (3 to 6mm), gnaw marks on food packaging and skirting, and a musky smell; you often hear scratching in walls or lofts at night. Rats leave larger, capsule-shaped droppings (up to 17mm), greasy smear marks along walls and runs, gnawing on harder materials, and sometimes burrows outside.
Both are mainly active at night, so signs like fresh droppings, disturbed food, shredded nesting material and noises after dark are often the first clues rather than seeing the animal itself.
How serious is it?
High: a health and property risk that breeds fast if ignored
Rodents are a genuine health and property concern. They can contaminate food and surfaces with droppings and urine, are associated with several diseases, and gnaw cables and pipes, which can cause electrical faults and leaks.
They also breed quickly, so a small problem can become an established infestation if ignored. Early action, and finding how they are getting in, is what keeps it manageable.
How to fix it yourself
- Find and block entry points. Mice can pass through gaps as small as a pencil, so seal holes around pipes, vents and doors with wire wool and proofing, and fit door brushes.
- Remove food and harbourage: store food in sealed containers, clear spillages, secure bins and tidy clutter and garden waste near the house.
- Set traps (snap traps placed against walls on the runs) for a small mouse problem, following instructions carefully.
- Use rodenticide only strictly per the label and out of reach of children and pets, or leave it to a professional, as misuse is dangerous and can poison wildlife.
- Keep checking and re-proofing, as rodents exploit any remaining gap.
When to call a professional
- Signs of more than the odd mouse, any rats, or an infestation that persists after proofing and trapping.
- Rodents in a property you cannot fully proof, in shared buildings, or where safe rodenticide use is needed.
Who to call
- Your local council pest control service, which deals with rats and mice in many areas, sometimes free of charge.
- A BPCA or NPTA member pest controller for proofing, trapping and safe rodenticide treatment.
Indicative cost: Council treatment may be free or low cost; private rodent treatment commonly from around 95 to 250 pounds. Prices vary by area, severity and access, so always get a written quote.
Frequently asked questions
How do I know if I have mice or rats?
Mice leave small rice-grain droppings, gnaw marks on packaging and a musky smell, often with scratching at night. Rats leave larger capsule-shaped droppings, greasy smears along walls, heavier gnawing and sometimes outdoor burrows. The size of the droppings is the quickest guide.
Are mice and rats dangerous to health?
They can be. Rodents contaminate food and surfaces with droppings and urine, are linked to several diseases, and gnaw wiring and pipes, which can cause fire and water risks. This is why a rodent problem should be dealt with promptly rather than ignored.
Will my council get rid of rats for free?
Many councils provide pest control for rats and mice, and some treat rodents free of charge, though this varies by area. Check your local council pest control page on gov.uk to see what is offered and whether there is a charge where you live.
Can I get rid of mice myself?
A small mouse problem can often be managed by blocking entry points, removing food sources and setting snap traps. For rats, repeated infestations, or anywhere you cannot fully proof, a professional or your council pest service is the safer choice.
Sources
Editor, HomesAndHedge
Oliver leads HomesAndHedge's editorial coverage of home and garden problems. He researches and writes the plain-English explainers on pests, invasive plants, damp and mould, drainage and wildlife, drawing on guidance from bodies such as the Property Care Association, the RHS and the NHS, and is clear about when a job needs a qualified professional.
Last reviewed: 8 June 2026