How to Get Rid of Mice in Your House: A Complete UK Guide (2026)

If you’ve heard scratching in the walls after dark, or found a scattering of small droppings behind the kettle, you’re probably dealing with mice. I’ve spent a lot of time talking to homeowners about this, and the pattern is almost always the same: they hear something once, tell themselves it’s nothing, and three weeks later they’re dealing with a proper infestation. Mice breed fast — a single female can have five to ten litters a year — so the sooner you act, the easier this is to sort out.

This guide walks through how to confirm you actually have mice, why they got in, which DIY methods genuinely work, and when it’s time to stop DIY-ing and bring in a professional.

Signs You Have Mice in Your House

Mice are nocturnal and naturally cautious, so you’re more likely to find evidence of them than to see one running across the kitchen floor. The most reliable signs, in rough order of how often they show up, are:

Droppings. Small, dark, rod-shaped, about the size of a grain of rice. You’ll usually find them in cupboards, along skirting boards, or near food packaging.
Gnaw marks. Mice need to wear their teeth down, so they chew cardboard, wood, cables, and food packaging. Chewed cereal boxes are a classic early sign.
Scratching noises. Usually at night, in walls, under floorboards, or in the loft, as mice move around once the house goes quiet.
A stale, musty smell. Mouse urine has a distinct ammonia-like odour that builds up in enclosed spaces like cupboards and lofts.
Smear marks. Mice tend to run along the same routes, and the grease and dirt on their fur leaves faint dark smudges along skirting boards over time.

How Mice Get Into Your Home

A mouse can squeeze through a gap around the width of a pencil — roughly 6mm — because its skull is the limiting factor, not its body. In older housing stock especially, common entry points include gaps around pipework under sinks, air bricks without mesh covers, worn door seals (especially on older external doors), gaps where cavity walls meet the roofline, and holes where cables or vents pass through external walls. Terraced and semi-detached houses are particularly prone to mice moving between neighbouring properties through shared cavity walls, which is why treating just one house in a row sometimes isn’t enough on its own.

DIY Mice Removal Methods That Work

For a mild to moderate infestation — a handful of mice rather than an established colony — DIY control is often effective if you’re consistent about it. The three main approaches are:

Snap traps. Still the most reliable single tool for most households. Modern plastic snap traps are easier to set and empty than the old wooden style, and they give you a quick, humane kill rather than a slow one. Bait with something sticky, like peanut butter or chocolate spread, rather than cheese — mice are drawn to high-calorie, high-fat foods more than the stereotype suggests.
Humane live-catch traps. These let you release mice unharmed, but you need to release them well away from the property (ideally over a mile, since mice can find their way back from shorter distances) and check the trap at least twice a day so the animal isn’t left without food or water.
Rodenticide (poison) baits. These can work, but they come with real risks — to pets, to wildlife, and to you if placement is wrong. In our research, this is the method most often used incorrectly by homeowners, and it’s also the one with the strictest legal rules attached.

Best Practices for Trap Placement

Placement matters more than the trap itself. Mice hug walls and rarely cross open floor space, so traps set in the middle of a room are almost always wasted. Set traps perpendicular to the wall, with the trigger end touching the skirting board, along the runways you identified earlier. Use several traps rather than one or two — five to ten spread across likely routes is realistic for an average kitchen and utility area. Leave traps unset with bait for a day or two first (“pre-baiting”) if you’re dealing with a wary, established population; it noticeably improves catch rates because mice are naturally suspicious of new objects in their environment.

Preventing Mice From Coming Back

Catching the mice you have is only half the job. To stop new ones moving in, seal external gaps with wire wool or a proper rodent-proofing sealant (not standard expanding foam, which mice can chew through), fit brush strips or door sweeps on external doors, cover air brick vents with fine mesh, and keep food in sealed containers rather than open packaging. Reducing clutter in lofts and sheds also removes the nesting material mice rely on, making your property a less attractive place to settle in the first place.

When to Call a Professional

DIY methods work well for early or mild infestations, but there are situations where a licensed pest controller is genuinely the better option rather than just the more convenient one. Consider calling a professional if you’re still finding fresh droppings or hearing activity after two to three weeks of consistent trapping, if you’re hearing mice in multiple rooms or in the loft and walls simultaneously (a sign of an established colony rather than a few strays), if you have young children, pets, or anyone in the household who is particularly vulnerable to the health risks mice can carry, or if you simply don’t want to handle rodenticide or dead animals yourself. A professional also has access to monitoring tools and entry-point surveys that go beyond what’s practical for most homeowners, and can advise on structural fixes if mice are getting in through the building fabric itself. There’s no shame in calling one in — persistent infestations are often a sign of an entry point you haven’t found, and a trained eye finds those faster than trial and error will.