Rats Under the House: Causes, Entry Points & Removal

“Rats under the house” can describe several different situations.

Depending on the home, rats may be:

• beneath a raised floor
• inside or beside a crawl space
• burrowing along the foundation
• moving beneath a pier-and-beam structure
• traveling around slab edges
• using a utility chase
• entering through gaps near the sill or subfloor

The rats may stay outdoors beneath the structure.

Or they may use the under-house area as a protected route into:

• walls
• garages
• basements
• kitchens
• attics
• other structural voids

Common signs include:

• burrows near the foundation
• rat-sized droppings
• larger tracks
• worn runways
• rub marks
• gnawing
• scratching beneath floors
• nesting material
• repeated sightings near foundation edges

The practical goal is to determine:

1. where the rats are actually moving
2. whether they are outside, beneath the structure, or inside a crawl space
3. which entry points connect the under-house area to the building
4. what food, water, or shelter supports the activity
5. how to remove active rats safely
6. when exclusion can be completed without trapping rats inside

This guide explains why rats get under houses, how to identify active routes, what to inspect, and how to stop the problem from returning.

What Does “Rats Under the House” Mean?

The phrase can refer to several structural conditions.

Raised Foundation or Pier-and-Beam Home

Rats may move beneath the subfloor around:

• piers
• beams
• joists
• skirting
• utility lines

Crawl-Space Home

Rats may enter the crawl space itself.

See Rats in the Crawl Space: Signs & Removal for the crawl-space-specific guide.

Slab Foundation

Rats usually cannot live inside a solid concrete slab.

They may instead burrow:

• along slab edges
• beside foundation transitions
• near utility penetrations
• beneath adjacent soil or landscaping

Basement Foundation

Rats may shelter outside along the foundation and then enter through lower-level openings.

See Rats in the Basement: Why They’re There & What to Do.

Why Do Rats Get Under Houses?

The area beneath or beside a house can provide:

• shelter from weather
• cover from predators
• protected soil
• warmth
• nearby water
• access to food elsewhere
• structural routes into the building

Rats prefer edges and protected travel paths.

Foundation walls, beams, utility lines, and under-floor framing can create routes that are safer than crossing open ground.

Are Rats Under a House Usually Norway Rats?

Norway rats are strongly associated with:

• ground-level activity
• burrows
• foundations
• basements
• crawl spaces

So under-house burrowing often fits Norway-rat ecology.

However, location alone does not identify the species.

Roof rats can also move through:

• lower wall cavities
• crawl spaces
• utility routes
• raised foundations

See Norway Rat: Identification, Signs & Behavior and Roof Rat vs Norway Rat: How to Tell Them Apart.

Can Roof Rats Go Under a House?

Yes.

Roof rats are more strongly associated with:

• attics
• rafters
• trees
• rooflines
• elevated travel

But they can use lower structural areas while moving between routes.

A rat under the house is not automatically a Norway rat.

Use:

• body features
• droppings
• tracks
• travel behavior
• broader building evidence

to support identification.

What Attracts Rats Under a House?

Common attractants include:

• pet food
• bird seed
• animal feed
• garbage
• fallen fruit
• compost
• stored food in garages
• standing water
• leaking pipes
• dense landscaping
• clutter near the foundation

The food source may not be directly under the house.

A rat can shelter beneath the structure while feeding in the yard, garage, kitchen, or neighboring property.

What Are the Main Signs of Rats Under the House?

Useful signs include:

• rat burrows
• rat-sized droppings
• larger tracks
• rub marks
• gnawing
• runways
• disturbed insulation
• nesting material
• scratching beneath the floor
• repeated sightings near the foundation

No single sign reveals how many rats are present.

See Signs of Rats: How to Tell If You Have Rats.

What Does a Rat Burrow Near a House Look Like?

A suspected rat burrow may appear near:

• foundation walls
• steps
• decks
• crawl-space vents
• sheds
• retaining walls
• dense vegetation

Possible signs of current activity include:

• smooth entry edges
• fresh soil
• worn runways
• nearby droppings
• repeated rat sightings

Do not assume every hole is a rat burrow.

Other animals can create similar openings.

Can Rats Burrow Under a Foundation?

Rats can burrow in soil beside structures.

They may use protected soil along:

• slab edges
• foundation walls
• footings
• retaining walls
• decks

Do not assume a burrow extends beneath a structural footing without evidence.

If soil movement appears to affect:

• foundation support
• drainage
• piers
• slabs

a qualified structural or pest professional may be appropriate.

Rats Under a Pier-and-Beam House

Pier-and-beam homes may provide rats with:

• open subfloor areas
• utility routes
• protected travel around piers
• gaps in skirting

Inspect the perimeter for:

• damaged skirting
• burrows
• droppings
• worn soil
• utility openings

Do not crawl under the house if clearance is low or conditions are unsafe.

Rats Around House Skirting

Skirting can hide under-house activity.

Possible signs include:

• gaps at the bottom
• gnawed openings
• worn routes
• soil disturbance
• droppings

Do not immediately seal every skirting gap if rats may still be inside.

Active-rat removal and monitoring should be coordinated with exclusion.

Rats Near Crawl-Space Vents

Foundation vents can become important entry points when:

• screens are missing
• mesh is damaged
• framing is loose
• gaps exist around the vent

Inspect from the exterior when possible.

A damaged crawl-space vent can connect under-house activity directly to the crawl space.

Rats Around a Crawl-Space Access Door

Access doors may develop:

• gaps
• damaged edges
• failed latches
• loose framing

Look for:

• gnawing
• rub marks
• droppings
• worn soil

Repairs should keep the access functional for future inspection.

Rats Entering Around Pipes and Utilities

Utility penetrations can connect the under-house area to:

• walls
• kitchens
• bathrooms
• mechanical rooms

Inspect around:

• water lines
• drains
• cable
• conduit
• HVAC lines

Do not damage utilities while inspecting or sealing.

Rats at the Sill or Rim Area

Raised foundations and crawl spaces may have openings where:

• foundation
• sill
• rim framing
• siding

meet.

Possible evidence includes:

• droppings
• rub marks
• gnawing
• visible gaps

Do not seal random structural joints without understanding their function.

Can Rats Move From Under the House Into Walls?

Yes.

Under-floor areas can connect to wall cavities through:

• utility chases
• framing gaps
• pipe openings
• damaged subfloor transitions

If sounds occur beneath the floor and inside nearby walls, the routes may be connected.

See Rats in Walls: Signs, Entry Points & What to Do.

Can Rats Move From Under the House Into the Kitchen?

Yes.

Plumbing and utility routes can connect lower structural areas to:

• sink cabinets
• appliance spaces
• wall cavities
• floor penetrations

If rat activity appears under the house and in the kitchen, inspect connected utility routes.

See Rats in the Kitchen: Why They’re There & What to Do.

Can Rats Move From Under the House Into the Garage?

Yes.

Garages often provide:

• door gaps
• utility openings
• stored food
• wall cavities

An under-house route can connect to an attached garage.

See Rats in the Garage: Entry Points, Nests & Control.

Can Rats Reach the Attic From Under the House?

Yes.

Rats can move upward through:

• walls
• plumbing chases
• utility routes
• framing voids

A ground-level entry point can eventually lead to attic activity.

See Rats in the Attic: Signs, Damage & Removal.

What Do Rats Under the Floor Sound Like?

Possible sounds include:

• scratching
• scurrying
• gnawing
• occasional thumping

But sound alone cannot confirm rats.

Possible alternatives include:

• mice
• plumbing
• ductwork
• building movement
• other animals

Use physical evidence to confirm the source.

Rat Droppings Under the House

Rat droppings may appear:

• near foundation edges
• beside piers
• near vents
• around utility penetrations
• along access paths

Do not use dropping count to estimate population size.

See Rat Droppings: What They Look Like & What They Mean.

Rat Tracks Under the House

Tracks may appear in:

• dust
• soil
• mud
• vapor barriers
• unfinished surfaces

Rat tracks are larger than mouse tracks.

See Rat Tracks: What They Look Like & Where to Find Them.

Rat Runways Under the House

Repeated movement may create worn paths along:

• foundation walls
• beams
• skirting
• utilities
• stored materials

A runway is stronger evidence when combined with:

• droppings
• tracks
• rub marks
• sightings

Rat Rub Marks Under the House

Repeated contact can create greasy-looking marks along:

• framing
• pipes
• foundation surfaces
• openings

Do not identify rats from a dark stain alone.

Dust, moisture, and ordinary grime can look similar.

Rat Gnaw Marks Under the House

Rats may gnaw:

• wood
• plastic
• soft trim
• insulation
• wire covering
• sealant around openings

Heavier gnawing becomes more meaningful with other rat evidence.

See Rat Gnaw Marks: How to Identify Rodent Damage.

Do Rats Nest Under Houses?

They can.

Possible nesting material includes:

• shredded paper
• cardboard
• fabric
• insulation
• soft debris

But ground-level Norway rats commonly use burrows.

A rat sighting under the house does not prove there is an exposed nest beneath the floor.

See Rat Nests: What They Look Like & Where to Find Them.

Is It Safe to Crawl Under the House?

Not always.

Do not enter an under-house space if there is:

• very low clearance
• standing water
• unstable supports
• damaged electrical wiring
• sewage
• heavy rodent contamination
• mold
• sharp debris
• aggressive wildlife
• difficult exit access

Inspect from the perimeter when possible.

Professional help is appropriate when safe access is uncertain.

How to Inspect From the Exterior

Walk the accessible foundation perimeter.

Look for:

• burrows
• damaged vents
• skirting gaps
• utility penetrations
• droppings
• runways
• gnawing
• foundation openings

Document where evidence appears.

The outside route often reveals enough information to plan the next step without entering the space.

What to Do Right After Finding Rats Under the House

A practical response is:

1. document where evidence appears
2. inspect the foundation perimeter
3. look for burrows, droppings, tracks, and runways
4. inspect crawl-space vents and access doors
5. inspect utility penetrations
6. remove accessible food sources
7. correct avoidable water sources
8. choose a safe control method
9. monitor for fresh activity
10. complete exclusion after active rats are addressed

Do not begin by sealing every opening or pouring something into a burrow.

Remove Food Sources Around the Foundation

Check for:

• pet food
• bird seed
• animal feed
• garbage
• fallen fruit
• compost
• outdoor food waste

Store vulnerable food in sturdy containers.

Clean repeated spills.

Food reduction supports removal but does not replace exclusion.

Reduce Water Sources

Inspect for:

• leaking outdoor faucets
• plumbing leaks
• irrigation problems
• standing water
• drainage problems

Keep necessary water available for pets and livestock.

Remove avoidable water sources only.

Reduce Shelter Near the Foundation

Possible shelter includes:

• dense ground cover
• stacked lumber
• stored containers
• debris
• unused materials

Focus on areas that:

• hide burrows
• block foundation inspection
• protect active rat routes

Do not destabilize storage or structural elements while cleaning.

Should You Flood a Burrow Under the House?

No.

Flooding can:

• redirect rats
• damage soil
• affect drainage
• affect foundations
• harm non-target animals
• fail to solve the problem

Do not pour large amounts of water into suspected burrows.

Should You Smoke, Burn, or Gas Rats Out From Under the House?

No.

Do not use:

• fire
• smoke
• gasoline
• engine exhaust
• improvised gases
• household chemicals
• boiling water

under a house or inside burrows.

These methods can create serious:

• fire
• poisoning
• structural
• environmental

hazards.

Should You Collapse Rat Burrows Immediately?

Not blindly.

If a burrow appears active, coordinate it with the broader control plan.

Simply collapsing the opening may:

• redirect rats
• cause new digging
• make monitoring harder
• leave the food and shelter problem unchanged

Treat burrow closure as a later step after active rat control.

Where Should You Put Rat Traps for Under-House Activity?

Use rat-sized traps on confirmed accessible routes.

Possible locations include:

• along exterior foundation edges
• near accessible crawl-space entry routes
• along stable under-floor framing when safely reachable
• near utility routes
• inside a suitable protected trapping setup

Keep traps:

• stable
• accessible for checking
• away from children and pets
• protected from birds, squirrels, and wildlife

See Rat Traps: Types, Placement & How to Use Them and Best Rat Traps: Which Type Works Best & How to Choose.

Should You Put Traps Deep Under the House?

Not if they cannot be:

• checked
• retrieved
• kept stable
• protected from non-target animals

A trap in an inaccessible location is difficult to monitor.

Use the safest accessible route available.

Should You Use Poison Under the House?

Do not scatter loose rodenticide beneath the house.

Rodenticides must be used according to:

• the product label
• applicable laws
• placement requirements
• child and pet safety requirements

Where a product requires a secured bait station, use an appropriate tamper-resistant station.

A poisoned rat may die:

• beneath the floor
• in a wall
• in a crawl space
• in another inaccessible void

and create a strong odor problem.

Should You Seal Foundation Gaps Immediately?

Not always.

If rats are already inside and you seal the only active route, they may:

• move deeper into the building
• enter another room
• gnaw another opening
• die in an inaccessible void

Coordinate removal, monitoring, and exclusion.

See Rodent Exclusion: How to Keep Rats & Mice Out.

How to Seal Under-House Entry Points

The correct repair depends on the opening.

Possible durable materials include:

• metal mesh
• flashing
• mortar
• rodent-resistant backing plus suitable sealant
• repaired vent screening
• repaired access doors
• properly repaired skirting

Do not block:

• drainage
• ventilation
• required combustion air
• utility access
• structural inspection access

Repairs must fit the building design.

What About Crawl-Space Ventilation?

Do not close vents simply because rats are nearby.

Ventilation requirements depend on:

• building design
• local code
• moisture-control strategy

Repair damaged vent screening without defeating the intended ventilation system.

Can Rats Damage Wiring Under the House?

Yes.

Rats can gnaw wire insulation.

If wiring appears damaged:

• do not touch exposed conductors
• keep people away from unsafe wiring
• have electrical damage evaluated appropriately

Do not work around energized systems unless qualified.

Can Rats Damage Insulation Under the House?

Yes.

Rats may:

• compress insulation
• pull material into nests
• contaminate it
• create travel routes

See Rats in Insulation: Signs, Damage & Cleanup.

How to Clean Rat Droppings Under the House Safely

If a small contaminated area is safely accessible:

1. keep unnecessary people and pets away
2. wear suitable gloves
3. avoid stirring up dust
4. wet droppings or nesting material with an appropriate disinfecting solution
5. allow the product’s required contact time
6. collect the waste carefully
7. bag it appropriately
8. clean nearby hard surfaces
9. wash hands after removing gloves

Do not dry sweep or vacuum fresh rat droppings or nesting material before wet cleanup.

See the cleanup section and rodent safety section.

What About Heavy Contamination Under the House?

Professional cleanup may be more appropriate when:

• droppings are widespread
• several nesting areas are present
• insulation is heavily contaminated
• access is difficult
• standing water or sewage is present
• wiring hazards exist

Do not enter an unsafe space simply to clean it.

How to Know Whether the Problem Is Improving

Monitor for:

• no new droppings
• no new tracks
• no reopened burrows
• no new gnawing
• no new rub marks
• no trap activity
• no repeated sightings
• no continuing scratching beneath floors

One quiet day is not proof that rats are gone.

Look for the absence of fresh evidence over time.

When to Call a Professional

Professional rat control may make sense when:

• active burrows are beneath or against the foundation
• rats are entering the crawl space or house
• under-house access is unsafe
• structural supports may be affected
• wiring is damaged
• contamination is extensive
• trapping locations cannot be protected
• the entry route cannot be found
• exclusion requires foundation or construction repair
• you are unsure how to use rodenticide legally and safely

See Rat Exterminator: What to Expect & When to Call One.

Rats Under the House: The Bottom Line

Rats may get under houses because the area can provide:

• shelter
• protected soil
• warmth
• travel routes
• access to utilities
• proximity to food and water
• entry into the structure

Useful signs include:

• burrows
• rat-sized droppings
• tracks
• runways
• rub marks
• gnawing
• scratching beneath floors
• repeated sightings

If you find rats under the house:

• inspect the exterior perimeter first
• identify whether activity is outdoors, beneath the structure, or inside a crawl space
• remove accessible food and unnecessary water
• inspect vents, skirting, access doors, and utility penetrations
• do not flood, smoke, burn, gas, or pour chemicals into burrows
• use rat-sized traps only on safe accessible routes
• use rodenticides only according to the label and applicable requirements
• coordinate active-rat control with exclusion
• preserve drainage, ventilation, utilities, and structural access
• monitor until fresh signs stop

The long-term solution is not simply sealing the underside of the house.

It is identifying the actual rat route, removing active rats safely, and correcting the structural openings that allow activity to continue.

Continue with our rats in the crawl space guide, rats under a deck guide, rats in the yard guide, rat droppings guide, rat tracks guide, rat gnaw marks guide, Norway rat guide, how to get rid of rats, how rats get into a house, or rodent exclusion guide.

For the broader overview, return to [Rats & Mice in the Home](/).