A house mouse infestation requires immediate action due to the rodents’ rapid reproductive cycle and potential for structural damage. Mice seek warmth and food, especially as the weather cools, and can fit through incredibly small spaces to gain entry. Addressing a mouse problem prioritizes exclusion, effective removal, and strict health safety protocols. Successful strategies combine proactive prevention with targeted mechanical or chemical intervention.
Preventing Mice Entry Points
Mice can squeeze through gaps as small as 5 to 6 millimeters, making a thorough inspection of the building exterior essential. Common vulnerabilities include openings around utility lines, such as gas, water, and heating pipes where they enter the wall structure. These gaps must be sealed with materials that mice cannot chew through.
Recommended exclusion materials include coarse wire wool or galvanised steel mesh (typically 5mm aperture), which should be firmly packed into the holes. Expanding foam should not be used alone, as mice can easily gnaw through it; it must be combined with wire wool or cement. Other entry points to check are damaged mortar, poorly sealed window frames, and spaces around air bricks and vents, which need fine-mesh covers to maintain ventilation while blocking access.
Spaces beneath external doors, especially garage doors, require the installation of bristle strips or specialized excluders. Regularly inspecting and maintaining the integrity of the home’s perimeter is the most effective long-term defense against re-infestation. Eliminating access points makes your property structurally inhospitable to rodents seeking shelter.
Mechanical Removal Methods
Mechanical methods offer lethal and humane options for removing mice once they are inside the property. Traditional snap traps are highly effective when placed correctly, set perpendicular to walls along known mouse runways, with the trigger side facing the skirting board. Baiting these traps with sticky foods like peanut butter or chocolate spread is often more effective than cheese. For a small infestation, use multiple traps—at least six for every two mice suspected.
For those preferring a humane approach, catch-and-release traps capture the mouse unharmed but require careful handling and relocation. Mice possess a strong homing instinct, so the trapped rodent should be released a minimum of two miles away from the capture site to prevent return. Release should occur in a suitable, vegetated area, and the trap must be checked frequently, ideally every few hours, to minimize stress on the animal.
Homeowners in the UK must be aware that the use of glue traps is now illegal for the general public. Following the implementation of the Glue Traps (Offences) Act 2022 in England and Wales, the legislation prohibits their use by unlicensed individuals due to welfare concerns.
When to Use Chemical Control and Professionals
If mechanical trapping proves unsuccessful or the infestation is large, chemical control using rodenticides is an option, though it is heavily regulated in the UK. Amateur-use rodenticides are restricted in both strength and quantity to mitigate risks to non-target animals, pets, and children. These products contain a lower concentration of active anticoagulant substance, and pack sizes are limited, such as a maximum of 300g for block baits.
All rodenticide baits must be placed inside tamper-proof bait stations, which prevents pets and children from directly accessing the poison. Open baiting, where poison is left exposed, is illegal in the UK and poses a significant threat to wildlife through primary and secondary poisoning. Follow the product label instructions precisely, as misuse can lead to serious consequences.
If the infestation is severe, widespread, or inaccessible, contact a professional pest control service. Professionals have access to stronger, professional-use-only rodenticides and specialized equipment. They are trained to address complex infestations while adhering to Campaign for Responsible Rodenticide Use (CRRU) guidelines. They can also identify hidden entry points and nesting sites that a homeowner may miss, providing a more comprehensive solution.
Post-Infestation Cleanup and Health Safety
Once the mouse problem has been eliminated, cleanup is necessary to mitigate health risks associated with droppings, urine, and nesting materials. Before cleaning, ventilate the affected area for at least 30 minutes by opening windows and doors to disperse airborne contaminants. Wear protective equipment, including disposable gloves and an FFP1 or FFP2 dust mask, to prevent the inhalation of potentially harmful particles.
Never sweep or vacuum droppings and nesting material immediately, as this can aerosolize dust containing pathogens like the bacteria that cause Salmonellosis. Instead, spray the contaminated areas with a household disinfectant or a bleach solution (one part bleach to ten parts water) and allow it to soak for five minutes to kill viruses and bacteria. The waste should then be carefully wiped up with paper towels, sealed in a plastic bag, and disposed of in the general outdoor waste bin.
After removing all visible contamination, the entire area must be disinfected again, and all reusable cleaning equipment should be sanitized before storage. While the risk of Hantavirus is low in the UK, proper sanitation remains important to prevent infection from other diseases carried by rodents, and any contaminated food sources must be immediately discarded.