How to Get Rid of Rats Under Floorboards Safely

If you need to know how to get rid of rats under floorboards, the first step is to confirm where they are entering and whether they are confined to the subfloor void. Avoid sealing openings or placing poison beneath the floor without a proper inspection. You could trap rats inside the building, create an inaccessible carcass or cause them to move into walls and other rooms.

Rats beneath a floor are rarely just a noise problem. They may contaminate the void, damage cables and pipework, or use the space as a protected route through the property. Effective control must address the rats already present and the defect that allowed them inside.

How to get rid of rats under floorboards

A lasting solution normally involves four connected stages:

1. Confirm that the noise or evidence is caused by rats.

2. Identify how they entered the building and reached the floor void.

3. Control the active infestation safely.

4. Proof the access points at the correct time.

Removing a rat without fixing its route into the property leaves the building open to another infestation. Equally, sealing every suspected gap before dealing with active rats can make the situation worse.

The safest approach depends on the construction of the property, the location of services beneath the floor, whether children or pets are present and whether rats are also using drains, wall cavities or neighbouring buildings.

Signs of rats beneath the floor

Scratching beneath the floorboards is a common warning sign, particularly when it happens at night. However, noise alone does not prove that you have rats.

Evidence that supports a rat diagnosis includes:

• Heavy scratching, scurrying or gnawing sounds

• Noises that follow a repeated route beneath the floor

• Rat droppings near gaps, cupboards or service pipes

• Greasy marks along walls or around openings

• Damaged food packaging

• Gnawed timber, plastic, cables or pipe insulation

• A stale or ammonia-like smell

• Pets repeatedly focusing on one area of flooring

• Burrows or disturbed ground beside the outside wall

• Activity around drains, air bricks or extensions

Rats are generally heavier and louder than mice. Mice can still sound surprisingly active in a quiet house, so the volume of the noise is not conclusive.

Expansion and contraction of pipes, loose fittings, birds, squirrels and movement elsewhere in the structure can also be mistaken for rodents. A competent survey looks for physical evidence rather than relying only on what has been heard.

How do rats get under floorboards?

In many British homes, suspended timber floors sit above a ventilated subfloor void. That void can provide shelter, darkness and routes for pipes, drains and cables. If there is a defect at the building perimeter or drainage system, rats may gain access without entering a room first.

Common entry routes include:

• Broken or unprotected air bricks

• Gaps around waste pipes and utility services

• Damaged drains or redundant pipework

• Openings beneath external doors

• Voids created during an extension or renovation

• Defective masonry at ground level

• Gaps between adjoining properties

• Poorly sealed ducts and cable entries

• Access from cellars, basements or attached garages

• Burrows reaching the foundations or floor void

Rats are capable climbers and persistent gnawers. A route does not always need to be directly beside the room where the noise is heard. They may enter at one side of the building and travel beneath several rooms.

Can rats chew through floorboards?

Rats can gnaw timber, particularly at an existing edge, damaged section or gap. An intact floorboard is not usually the easiest route into a room, but persistent rats may enlarge weaknesses around pipes, corners and previous repairs.

Their teeth can also damage plastic, soft metals, insulation and electrical cable coverings. Any suspected cable damage should be assessed by a suitably qualified electrician.

Visible damage does not necessarily show where the rat first entered the building. It may only identify the point where it attempted to move from the subfloor void into the occupied room.

Why have rats chosen the space beneath your floor?

The floor void provides protection, but there is usually another reason rats remain in or around a property.

Likely attractions include:

• Accessible food in kitchens, cupboards or storerooms

• Pet food left out overnight

• Bird seed and food dropped beneath feeders

• Unsecured household waste

• Poorly managed compost

• Animal feed in sheds or garages

• Leaking pipes or standing water

• Warmth from the building

• Undisturbed nesting material

• A nearby drainage defect

• Food sources in an adjoining property

Removing accessible food and water makes control more effective, but housekeeping alone will not close an established structural route.

Rats may also be moving through the floor without nesting directly beneath it. Inspection should establish whether the void is a feeding site, nesting location or travel route.

What not to do when rats are under the floor

Some quick solutions can create additional problems or obscure the evidence needed to locate the source.

Do not immediately seal every opening

Proofing is essential, but active rats must not be trapped inside. They may gnaw into occupied rooms, move into wall cavities or die in an inaccessible space.

Establish which routes are active and plan the control and proofing sequence before closing them.

Do not put loose poison beneath the floor

Rodenticide should never be scattered into a void or placed where it cannot be inspected and recovered.

A poisoned rat may die somewhere inaccessible, causing a persistent smell and attracting flies. Loose bait may also be moved, contaminate the area or expose pets and other animals.

The Health and Safety Executive’s rodenticide guidance explains that these products can present risks to people, pets, wildlife and the environment. Chemical control should form part of an assessed strategy rather than being the automatic first response.

Do not rely on ultrasonic devices

Results from ultrasonic deterrents are inconsistent. Even where rats initially react to a sound, they may become accustomed to it when food and shelter remain available.

A deterrent does not repair a broken drain, proof an air brick or remove an established infestation.

Do not flood burrows

Flooding a suspected burrow may push rats towards the building or another exit. It can also damage foundations, saturate the subfloor area and disperse contamination.

Do not lift flooring without considering services

Pipes, electrical cables and other services may run immediately below the boards. Older flooring can also be difficult to lift without damage.

If access is necessary, it should be planned carefully and limited to the area most likely to provide useful evidence or safe treatment access.

Do not use glue traps

Glue traps cause serious welfare concerns and are not an appropriate casual solution. Any control method must be lawful, proportionate and selected with animal welfare and non-target risks in mind.

Can you deal with rats beneath the floor yourself?

Minor proofing and prevention work may be reasonable when there is no evidence of an active infestation. For example, you can secure food, manage waste and repair an obviously damaged bin.

Active rats beneath a floor are more difficult because the treatment area is hidden and may contain drainage, electrical or structural defects.

Before attempting any control, you would need to understand:

• Whether the pest is definitely a rat

• How many areas show activity

• Where the rats enter the property

• Whether an active nest is present

• Whether drains may be involved

• Whether traps can be positioned, secured and checked safely

• Whether children, pets or wildlife could reach the equipment

• How dead rodents and contaminated material will be removed

• When each access point should be proofed

If these questions cannot be answered confidently, arrange a professional inspection.

How professional rat control beneath floors works

A professional treatment should not consist of simply leaving bait and hoping the noise stops. The work should be based on evidence from the property.

1. Inspection

The technician will examine likely entry points, food sources and signs of movement. Relevant areas may include:

• The outside perimeter

• Air bricks and vents

• Pipe and cable penetrations

• Kitchens and utility rooms

• Cupboards and boxed-in services

• Sheds, decking and extensions

• Inspection chambers and visible drainage features

• Adjoining structures

• Accessible areas beneath the floor

The survey should also consider whether the rats are entering from a neighbouring property or shared drainage system.

2. Species and activity assessment

Fresh droppings, gnawing, footprints, grease marks and monitoring evidence can help confirm the pest and determine whether the route remains active.

This matters because treatment for a rat beneath a suspended floor may differ from the response to mice in a wall, a squirrel in a roof or an isolated noise from pipework.

3. Control plan

The control method should reflect the building and the risks present. It may include monitoring, traps, targeted baiting or a combination of measures.

Equipment must be placed securely and checked at appropriate intervals. If rodenticide is justified, it should be used according to its authorised label and UK stewardship requirements.

No treatment can honestly be described as entirely risk-free. The aim is to choose and manage the most appropriate method while minimising risks to residents, pets, wildlife and the environment.

4. Proofing

Once the active problem has been controlled, entry points can be repaired using materials appropriate to the defect.

Possible work includes:

• Protecting or repairing air bricks

• Sealing gaps around service pipes

• Repairing damaged masonry

• Closing redundant ducts

• Correcting door gaps

• Installing suitable rodent-resistant mesh

• Referring defective drains for specialist repair

Expanding foam on its own is rarely adequate where rodents can reach it. Proofing should be resistant to gnawing and should not obstruct necessary ventilation.

5. Follow-up monitoring

The absence of noise for one night does not prove that the infestation has ended. Follow-up checks help confirm whether activity has stopped and whether proofing has been successful.

Monitoring is especially important when access is limited or the original route involved shared structures.

What if a rat dies beneath the floor?

A dead rat beneath the floor can cause a strong smell that may persist while the carcass decomposes. The duration varies with temperature, airflow, moisture and the size and location of the animal.

You may also notice flies appearing indoors if insects can travel from the carcass into the room.

Where the location is known and can be reached without causing disproportionate damage, removal is preferable. If it is inaccessible, ventilation and odour management may reduce the immediate nuisance, but sprays will not remove the source.

A persistent smell should not automatically be attributed to a dead rat. Drainage faults, damp material and other dead animals can produce similar odours.

If floor access is required, weigh the likely benefit of removal against the potential damage to finished flooring and nearby services.

Cleaning droppings and contaminated areas

Rat urine and droppings can carry harmful microorganisms. Avoid handling them with bare hands.

Do not dry sweep or vacuum droppings, as this can disturb contaminated dust. Where a small accessible area can be cleaned safely:

1. Keep children and pets away.

2. Ventilate the room where practical.

3. Cover cuts and wear disposable gloves.

4. Dampen the contamination using a suitable disinfectant.

5. Allow the product’s stated contact time.

6. Lift the material with disposable towels.

7. Double-bag the waste.

8. Clean the surrounding hard surface.

9. Remove gloves carefully and wash your hands thoroughly.

Follow the disinfectant label and never mix cleaning chemicals.

Large deposits, contaminated insulation, inaccessible voids and areas affected by extensive urine or nesting material may require specialist cleaning.

The HSE notes that exposure to rat urine can transmit leptospirosis, although severe infection is rare in the UK. Seek medical advice if you become unwell after relevant exposure and tell the healthcare professional about the contact.

How to prevent rats returning beneath the floor

Prevention should remove both access and attraction.

Protect the building perimeter

Inspect low-level masonry, air bricks, doors and service openings. Repairs must preserve ventilation and other building functions.

Maintain drains

Recurring activity near toilets, soil pipes, extensions or inspection chambers may indicate a drainage issue. Pest control can address the rats, but damaged drainage may require a drainage contractor.

Store food securely

Keep dry food and pet supplies in robust containers with fitted lids. Clear spills promptly and avoid leaving pet bowls out overnight.

Manage bins and compost

Close bin lids fully, avoid waste accumulating beside the building and use a managed composting system. Do not place easily accessible cooked food into an open heap.

Reduce outdoor shelter

Clear unnecessary stored materials, cut back dense vegetation next to the property and inspect beneath sheds and decking.

Coordinate with neighbours where necessary

Rats do not respect property boundaries. In terraced, semi-detached or commercial buildings, treating one unit without addressing a shared route may only move the activity.

When should you call a pest controller?

Arrange an inspection when:

• Scratching continues for several nights

• Droppings or gnawing are present

• Rats are entering occupied rooms

• You cannot identify the access point

• Activity appears linked to drains

• Children or pets limit safe treatment options

• Electrical cables may have been damaged

• A strong smell or flies suggest an inaccessible carcass

• Previous control attempts have failed

• The building shares voids or services with neighbours

• You manage a commercial or food-handling property

GEM Services is based in Ashford and provides professional rat control across Kent for residential and commercial properties.

Our fully insured team offers fast, discreet inspections and same-day appointments where possible. We identify the route, explain the available control options and provide honest advice without pressure.

For related advice, read our guides to rats in drains, rats in the garden and signs of rats in a loft.

Call 07400 372204 or request a callback.

Frequently asked questions

Can rats live under floorboards?

Yes. A subfloor void can provide a protected nesting site or travel route, particularly where rats have access to food, water and an external or drainage-related entry point.

How long can rats live beneath a floor?

They can remain as long as the space provides shelter and they can reach food and water. Waiting for them to leave voluntarily is unreliable.

Will rats come through the floorboards?

They may enlarge existing gaps or weaknesses, particularly around pipework, damaged boards and edges. An intact board is less likely to be their easiest route.

Can rats damage electrical wiring beneath floors?

Yes. Rats can gnaw cable coverings, creating a risk of faults or fire. Ask a qualified electrician to inspect suspected damage.

Will poison get rid of rats beneath the floor?

Rodenticide may be appropriate in some professionally assessed situations, but it is not a simple or risk-free answer. An inaccessible rat may die beneath the floor, and unsafe bait placement can endanger people, pets and wildlife.

Should I seal a rat hole immediately?

Not until you know whether rats are still inside and whether the opening is an active route. Premature sealing may trap them within the building or cause them to find another way into occupied rooms.

Why can I hear rats only at night?

Rats are often most active when a property is quiet. Night-time noise does not reveal how many rats are present or prove that they remain beneath the same room during the day.

Do rats beneath floorboards mean the house is dirty?

No. Poor food and waste management can contribute, but rats also enter well-kept properties through damaged drains, structural defects and shared building voids.