How to Get Rid of Mice in the Walls

Dealing with mice in the walls of your home or business can be nightmare because these rodents are a nuisance that pose significant risks to your property. Mice have a tendency to chew on building materials like wood, drywall, plastic pipes, and electrical wiring which can lead to extensive damage and even pose risks of fire hazards and water damage. Additionally, their presence in your walls could indicate a larger infestation somewhere inside your building somewhere difficult to reach and treat.



To effectively rid your walls of mice, several steps should be taken. Firstly, identify and seal any entry points to prevent further intrusion. This involves inspecting the exterior of your home for cracks, holes, or gaps and sealing them with appropriate materials that mice can’t chew through. Use traps strategically placed near suspected entry points and along the walls to capture and exterminate any existing mice. In cases of severe infestation, it might be necessary to employ professional pest control services because they have the expertise and tools to deal with the problem comprehensively. 

Where Do Mice Hide?

Mice are experts at finding and inhabiting concealed spaces within homes which make them challenging pests to detect and eliminate. Common hiding spots include storage spaces, attics, lofts, and especially within wall interiors. Due to their small size, mice can squeeze through surprisingly tiny openings in floors, walls, and foundations which can give them easy access to various parts of a house.



Once inside, mice tend to remain hidden to avoid detection and typically come out at night when the inhabitants of a home are sleeping. During the day, their presence within walls can be detected through sounds of mice gnawing and scratching. Before implementing extermination strategies, it's crucial to confirm that the culprits are indeed mice, as other pests like rats or squirrels might also inhabit similar areas and would require different pest control approaches. 

How Do Mice Enter a Home

Mice are remarkably skilled at entering homes and can take advantage of the smallest of openings. Due to their flexible bodies, they can squeeze through tiny spaces and cracks in walls, floors, and foundations. Their excellent climbing abilities also enable them to access higher points of entry like gaps in exterior walls or roofs. Another exploitable area where mice can gain access is areas where there are thin or damaged building materials that mice can chew through. These rodents are persistent creatures that can use their teeth to chew through all sorts of building materials including drywall, wood, plastic, and siding. Once inside, mice quickly establish nests and begin reproducing at a rapid rate. A single female can produce multiple litters per year, each containing several offspring. This ability to rapidly populate makes it crucial to promptly address any signs of mice and to seal potential entry points to prevent infestations.

Can Mice Climb Walls?

Mice possess impressive climbing skills which enable them to scale most vertical surfaces that have a rough enough texture to grip. Their agility extends to jumping abilities as well as mice can leap many times their body length, reaching lengths of up to 18 inches. This ability to climb and jump gives mice an advantage when seeking out access points that other pests may not be able to find in addition to allowing them to use the elements within wall cavities as steppingstones to reach otherwise inaccessible areas of a home. This also makes them particularly elusive as it helps them to evade capture.

How Do Mice Get into Walls

Here are some common entry points and methods they use to gain access:



• Small Openings: Mice can squeeze through gaps as small as a dime which means that any small crack in your home's walls, ceilings, and floors can be a potential entry point.
• Utility Access: Mice often exploit the small spaces around utility pipes and wires to get inside a structure.
• Structural Weaknesses: Deteriorating siding, rotting drywall, cracks in foundations, and vents in brick walls can all serve as entry points for mice.
• Protected Coverage: If mice can gain access to covered areas like crawl spaces, decks, patios, and basements, they can usually use those spaces to get access to the interior of wall cavities.
• Building Gaps: Gaps in building materials, including poorly sealed door and window frames, provide easy access for mice.
• Ventilation Systems: Mice can also get into homes through air ducts, roof vents, and chimney pipes.

Once inside a building, mice use wall cavities to navigate and establish themselves throughout a home undetected. Sealing these potential entry points can help prevent mice infestations and the need for subsequent pest control measures.

Signs of a Mice Infestation in Your Walls

Recognizing the signs of a mice infestation within the walls of your home is crucial for timely intervention and control. Here are the common indicators that you might have mice hiding in your walls:



• Sounds: The most obvious sign is the sound of mice scurrying or squeaking inside the walls, especially at night since mice are nocturnal.
• Droppings: Look for small dark brown or black pellets in areas along walls and under furniture.
• Urine: Areas with a strong, ammonia-like smell indicative of mouse urine.
• Chew Marks: Visible chew or scratch marks on food packaging, shelves, baseboards, and around floor trim are telltale signs.
• Mice Holes: Mice often create small, clean-cut holes in drywall and siding that measure around 1.5 inches in diameter.
• Nests: Mice build nests from soft, shredded materials like fabric, paper, and pet hair that are often found in secluded areas like under cabinets or behind appliances.
• Mice Tracks and Grease Marks: You may notice tail and feet tracks on dusty surfaces or dark grease marks along walls and floorboards.
• Food Debris: Unusual crumbs or food debris in pantries, shelves, or on the floor can indicate mice foraging for food.
• Physical Sightings: Spotting live mice, particularly during daylight hours, is a strong indication of an active infestation.
• Pet Behavior: Unusual behavior from pets like barking or pawing at hidden spaces can signal they’ve detected mice.
• Odor: A musty odor often becomes noticeable in areas with large infestations.

What Do Mice Sound Like in Walls?

The presence of mice in walls is often first detected by the distinctive sounds they make. Homeowners frequently report hearing the telltale noises of mice activity within their walls and ceilings before actually seeing any of the rodents. Mice are nocturnal creatures which means they are most active during the night. If you hear sounds such as squeaking, skittering, scratching, or gnawing coming from your walls at night, it's a strong indicator that mice may have found their way into your home. These sounds are particularly noticeable in quiet environments and can vary from soft scratching to more pronounced gnawing noises as mice navigate through insulation, gnaw on wooden structures, or chew on electrical wiring. 

How to Catch Mice Living in the Walls

Dealing with mice living in the walls requires a strategic approach using various types of traps. Here are different traps you can use to effectively catch mice:



• Snap Traps: These are a common and affordable trap that is designed to quickly snap shut and kill the mouse instantly. They are easy to set and dispose of but should be placed in areas away from kids and pets due to the risk of accidental snapping.
• Automatic Multiple Catch Traps: These include wind-up-style and low-profile-style traps. Wind-up traps flip rodents into a holding chamber, while low-profile traps use a trap door mechanism that drops mice into a container like a bucket. They are suitable for larger infestations and require hands-on disposal of live mice.
• Glue Traps: These flat traps are coated with a sticky substance that captures mice when they walk over them. However, they are considered inhumane and less effective than other types, and thus not generally recommended.
• Live Traps: These traps are designed to catch and keep mice alive. However, live traps require extra effort for releasing the mice and are not legal in certain states like California.

When setting traps, it's important to bait them with attractive foods like peanut butter or seeds and place them in areas where mice are likely to travel. Use multiple traps, spaced about 6 feet apart, to increase your chances of catching mice. Regularly check, clean, and maintain the traps and be sure to replace them if they become less effective due to the scent of previously caught mice. For severe infestations, or if you are unsure how or where to use mice traps, consider consulting a pest control professional for tailored advice and solutions.

How to Use Rodenticides to Exterminate Mice Inside Walls

Using rodenticides can be a potent method for exterminating mice inside walls, particularly in cases of large infestations where other methods like trapping and sealing entry points have been insufficient. Rodenticides are special pesticides formulated to kill rodents, but it's crucial to use them safely and in accordance with label directions. There are two primary categories of rodenticides:

• Anticoagulants: These substances disrupt the mouse's blood clotting ability, leading to internal bleeding and death. The first-generation anticoagulants, such as warfarin, chlorophacinone, and diphacinone require multiple doses for effectiveness. Second-generation anticoagulants, like difethialone and brodifacoum, are designed to combat resistance to first-generation formulas. These are typically available as ready-to-use baits in pellet or block form.
• Non-Anticoagulants: These include ingredients like bromethalin, zinc phosphide, and cholecalciferol. Some non-anticoagulant rodenticides work with a single dose, while others require multiple doses. They kill mice through various mechanisms, none of which involve blood clotting.

Rodenticides are often packaged as food bait, containing common grains and seed mixtures. The baits come in various forms:



• Block and Pellet Baits: These are convenient and moisture-resistant which make them easy for rodents to consume. However, they can be carried off and hoarded by mice, raising concerns about pesticide translocation.
• Loose Meal Baits: These are less prone to relocation, but they can also absorb moisture which makes them unsuitable for damp or humid areas.
• Packet Baits: Small amounts of meal or pellets are sealed in a package which extends their usability and allows visual confirmation of rodent activity. However, they can also attract non-target wildlife, pets, and even children.

While rodenticides are effective, they pose hazards, and it's important to be aware of local laws regarding their use. Some states like California have specific laws that outlaw certain rodenticides. In cases of severe infestation or if safety is a concern, consulting a professional pest control service is recommended for effective and safe eradication of mice.

Safety Considerations When Dealing with Mice in Walls

When dealing with mice in the walls of your home, it’s important to prioritize safety for yourself, your family, and the environment. Here are recommended safety steps:

• Secure Pesticide Storage: Store all rodent baits, traps, and pesticides in a securely locked cabinet when not in use. Ensure these products are well-labeled and kept out of reach of children and pets.
• Indoor Bait Usage: Try to avoid using baits inside your home. Opt for traps, exclusion methods, and repellents as safer alternatives. If indoor baiting is necessary, use tamper-proof bait stations to protect children, pets, and non-target species.
• Follow Product Instructions: Always read and adhere to the label directions on any pesticides, rodenticides, and similar products to ensure correct and safe usage.
• Wear Proper Personal Protective Equipment (PPE): When handling pesticides, baits, or disposing of deceased mice, wear appropriate protective gear such as gloves, goggles, respiratory masks, and long sleeve shirts and pants to minimize exposure to harmful substances.

By following these safety precautions, you can effectively manage a mouse infestation while minimizing risks to health and safety. 

Rodenticide Safety Tips

When using rodenticides, especially in urban settings, adhering to safety protocols is crucial to protect yourself, your family, and the environment. Here are some important safety tips to follow:

• Secure Bait Placement: Always use rodenticide baits within tamper-proof bait stations, and ensure they are positioned out of reach of children, pets, and non-target wildlife to prevent accidental ingestion.
• Label Bait Stations: Clearly mark all bait stations with warnings such as "Rodent Bait – DO NOT TOUCH" to alert others of the potential hazard.
• Mindful Bait Positioning: Avoid placing bait in areas where they might be easily disturbed, knocked over, or bumped into.
• Avoid Loose Baits in Voids: Do not place loose bait blocks or packet-style baits in ceiling or wall voids, as rodents could move them, leading to unintended exposure.

By following these safety measures, you can mitigate the risks associated with rodenticide use. 

Ineffective Methods of Getting Rid of Mice Inside Walls

While there are numerous methods and home remedies suggested for controlling mice in walls, not all are effective, and some can even be counterproductive. Here are a few commonly mentioned tactics that lack evidence of effectiveness:



• Relying on Cats: While a cat might catch a few mice, they are generally insufficient for tackling an established mouse infestation. Additionally, mice can carry diseases and parasites that could be harmful to your pets.
• Mouse-Repellent Plants: Claims that strong-smelling plants like garlic, onions, lavender, daffodils, and mint deter mice lack scientific backing. These plants are unlikely to prevent mice from invading your home or garden.
• Ultrasonic or Hazing Devices: Devices like ultrasonic pest noise emitters or imitation predators may startle mice initially, but they quickly adapt to these stimuli and continue their normal activities.
• Fabric Softener Sheets: The strong scent of fabric softener sheets might initially repel mice, but they soon become accustomed to the smell, rendering this method ineffective.

For effective mouse control, especially for mice within walls, it's often necessary to use proven methods like mouse traps and baits or consult a professional pest control service for more comprehensive solutions.

Cleaning Up After a Mice Infestation

After successfully eliminating a mice infestation, thorough cleaning is crucial to prevent the spread of diseases associated with mouse droppings and urine. Here's a step-by-step guide on how to safely and effectively clean up after mice:



• Gather Protective Equipment: Wear heavy-duty rubber or latex gloves, a respirator or HEPA mask, and disposable coveralls to protect against exposure to harmful materials and pathogens.
• Ventilate and Disinfect the Area: Before cleaning, open doors and windows for 30-60 minutes to allow fresh air circulation. Use a commercial disinfectant or a homemade bleach solution (1 part bleach to 10 parts water) to spray and saturate all contaminated areas including urine stains, droppings, and nesting material. Allow the disinfectant to sit for at least five minutes.
• Wipe Up Droppings and Nest Materials: Using paper towels or disposable rags, carefully wipe up and remove the saturated droppings and nesting materials. Avoid using a broom or vacuum, as this can aerosolize hazardous particles. Double-bag the cleanup materials and dispose of them in an outdoor trash can.
• Wash Hands and Launder Clothing: After cleanup, thoroughly wash your hands with hot, soapy water. Launder any clothing worn under the coveralls in hot water with strong detergent.
• Monitor Your Health: Be vigilant for symptoms of hantavirus exposure like fever, fatigue, muscle pain, difficulty breathing, headaches, nausea, vomiting, diarrhea, and dizziness. Seek medical attention immediately if you experience any of these symptoms.

Following these steps will help ensure that your home is safely cleaned and that any health risks associated with a mouse infestation are minimized.

Dealing With a Dead Mouse Inside Your Walls

Dealing with a dead mouse inside your walls is an unfortunate but common issue during a mouse infestation. Mice may die within the walls for various reasons – they could succumb to rodenticides, get trapped in narrow spaces and starve, or simply pass away due to natural causes. A telltale sign of a deceased mouse within your walls is a distinct, unpleasant odor of decay that can become quite potent over time followed by an increase in fly activity due to maggots consuming the corpse and developing into flies.



Removing a dead mouse from inside a wall is a task that often necessitates professional intervention. In many cases, it involves cutting into the drywall. This requires careful inspection to identify where the dead mouse is and precise work to avoid unnecessary damage to your home's structure. Professionals have the expertise and tools to locate and remove the carcass effectively while minimizing disruption to your property. Prompt removal of the dead mouse is essential to prevent the spread of odors and potential health hazards associated with decaying animals.

Prevent Mice from Coming Back

After successfully eliminating mice from your walls, it's crucial to implement measures to prevent their return. Start by thoroughly inspecting your home and sealing any cracks, openings, or small holes that mice could use to gain entry. Pay special attention to areas around doors, windows, and utility lines, and ensure that any damaged screens are repaired. Another effective step is to maintain a clean and tidy home environment by storing food sources in airtight containers, regularly cleaning counters and floors to remove crumbs and food residues, and managing waste and storage areas to minimize potential nesting sites. These proactive steps create a less inviting environment for mice, significantly reducing the likelihood of a recurring infestation.

Eliminate Food, Water, and Shelter

To deter mice from taking up residence in and around your home, it's essential to eliminate their access to food, water, and shelter. Here are some effective strategies:



• Food Storage: Store all food, including grains, pet food, and dry goods in glass or metal containers that mice cannot chew through.
• Clean Eating Habits: Avoid leaving pet food out for extended periods and clean up spills and messes promptly. Implement a rule to eat only at the table to minimize crumbs and scraps around the house.
• Remove Nesting Materials: Store fabrics, rugs, and blankets in heavy-duty plastic storage bins to eliminate soft nesting materials.
• Maintain Dryness: Use dehumidifiers in areas like attics, crawl spaces, and basements to keep them dry and less inviting for mice.
• Proper Waste Management: Dispose of household recycling quickly, especially cardboard, paper, and lightweight plastics that mice can use for nesting.

Seal Access Points

Sealing access points is a critical step in preventing mice from entering your home and establishing residence in your walls. Here are some effective ways to seal these entry points:



• Foundation and Wall Cracks: Seal any cracks in your foundation and walls. Use materials that mice cannot gnaw through like wire/stainless steel mesh or quick-drying cement, instead of plastic, rubber, or wood.
• Inspect Vents: Check vents around your home, especially those in crawlspaces and attics. Place durable, rust-resistant wire screens over vents and chimney openings.
• Garage Door Seals: Ensure your garage door sweeps have no gaps and seal tightly against the ground.
• Caulk Small Openings: Seal tiny holes and gaps larger than ¼ inch in your foundation, siding, and doorways with caulk. Mice can squeeze through gaps as small as ⅜ inch wide.
• Repair Windows and Doors: Fix broken basement windows, warped doors, and damaged window screens to prevent entry.
• Utility Line Entrances: Seal gaps created by utility lines with materials like sheet metal, stainless steel fill fabric, hardware cloth, and mortar.
• Install Door Sweeps: Add door sweeps to all exterior doors to block gaps under the doors.
• Pipe Guards and Paint: Deter mice from climbing exterior pipes by adding guards made of 26-gauge sheet metal and painting a 12-inch glossy band around the bottom of vertical pipes.

Maintain Landscaping and Trim Vegetation

Maintaining your home's landscaping and keeping vegetation trimmed is an effective strategy in preventing mice from accessing your home. Mice are skilled climbers and jumpers, so it's important to create a barrier between your home and any greenery. Ensure that tree branches and shrubs are trimmed back at least a foot-and-a-half from your house. This distance makes it more challenging for mice to use vegetation as a pathway to upper levels of your home or as coverage from predators like cats and birds.



In addition to trimming, reducing yard debris and potential nesting sites around your property is crucial. Mice often build nests in hollowed stumps, dense bushes, rock piles, leaf piles, and woodpiles. If you have a woodpile, consider moving it further from your home, especially if it's near the foundation. Mice can use woodpiles as a steppingstone to gain entry into your walls. By keeping your yard clean and vegetation well-maintained, you reduce the likelihood of mice finding suitable nesting spots near your home and subsequently trying to invade your living spaces.

Contact EcoGuard if You Are Dealing with Mice

While the steps outlined can significantly aid in preventing and managing mice infestations within your walls, sometimes the challenge requires professional expertise. If you find yourself facing persistent issues with mice in your home, EcoGuard Pest Management is here to assist. Our team of experienced professionals is equipped with the knowledge and tools to effectively address your rodent problems. Don't let mice in your walls disrupt your peace and comfort, contact EcoGuard Pest Management today to schedule an appointment.

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