How to Tell If Rats Are Living in Your Walls (and What to Do About It)

A few garbage-related rat sightings are unsettling, but nothing compares to the moment homeowners realize something much worse may be happening: rats living inside the walls. It starts small — a faint scratch at night, an odd tapping sound, or that feeling that something is moving where it shouldn’t be.

The good news? Rats in walls leave very consistent signs, and once you know what to look for, you can confirm an infestation quickly and take action before major damage is done.

This guide walks you through the early warning signs, what’s actually happening inside those walls, and the safest ways to get rats out for good.

? 1. You Hear Scratching, Scurrying, or “Light Footsteps” at Night

Rats are nocturnal, so nighttime noises are a primary indicator. Sounds typically include:

Light rapid scurrying
Scratching inside drywall
Gnawing or chewing
Thumping behind the wall cavity
Occasional squeaks

If noises are happening mostly between 11 p.m. and 4 a.m., rats are highly likely.

Tip: Put your ear against the wall during quiet hours. If you hear movement that seems “inside” rather than from a neighbor or pipes, that’s a strong sign.

? 2. Rat Droppings Near Walls, Baseboards, or Behind Appliances

Even if droppings aren’t in the wall cavity itself, they tend to accumulate:

Behind the stove
In the basement
Near HVAC returns
Along the edges of rooms
Under sinks

Fresh droppings are dark and moist; older ones turn gray and dry.

If you haven’t yet, read:
? Why Rats Love Your Garbage Cans (and How to Keep Them Out)
This is often where the indoor rat problems begin.

? 3. Grease Smudges or “Rub Marks” on Walls

Rats run the same pathways repeatedly. Their oily fur leaves unmistakable dark streaks on:

Drywall
Electrical conduits
Baseboards
Foundation edges

If your wall has new smudges or discolorations that don’t wipe clean easily, rats may be slipping in and out of hidden openings.

?? 4. Small Holes or “Chew-Outs” Near Floor Level

Rats chew access holes around:

Pipes
Vents
Electrical outlets
Cracks in plaster
Utility penetrations

A typical rat hole is quarter-sized, often with rough, gnawed edges.

If you discovered rats chewing through your car wiring, this is a natural next step:
? Rodents Are Destroying Cars: Here’s How to Stop Them — And What Auto Insurance Actually Covers

? 5. Bizarre Electrical Issues (Yes, Rats Chew Wires)

If your lights flicker or breakers trip at random, rats may be chewing electrical insulation inside your wall cavities. This is dangerous for two reasons:

Fire hazard
Damage to expensive wiring that requires wall demolition to repair

If electrical anomalies coincide with any other signs on this list, take it seriously.

? 6. You Notice a Foul, Musky, “Warm” Odor

A rat nest has a very distinct smell — musky, slightly sour, and strongest near corners or radiators. If the smell comes from one particular wall, that’s the nest zone.

The odor becomes worse when:

Nesting materials accumulate
Rats urinate in the same area
A rat dies inside the wall

If you suddenly smell something rotten that lasts for days, it may be a deceased rat.

?? What to Do If You Suspect Rats in Your Walls

1. Seal Outdoor Entry Points

Focus on:

Gaps around AC lines
Foundation cracks
Holes near gas pipes
Openings behind siding
Trash areas (major attractant)

Your garbage setup still matters:
? 3 Best Rat-Proof High-Capacity Garbage Cans (once published)

2. Use Humane, Non-Poison Solutions First

Poison leads to rats dying inside walls — which creates a horrific smell and sometimes requires tearing open drywall.

Instead, use:

ContraPest (fertility control) — safe, EPA-approved, reduces population over time
Snap traps in sealed boxes
Ultrasonic repellers in basement/attic access points

You can safely mention ContraPest again for internal reinforcement.

3. Call a Professional if You Hear Daily Movement

Persistent scratching means multiple rats or a nest with young. Professionals can:

Scope walls with an inspection camera
Identify where rats breach siding
Seal areas you wouldn’t think to check
Remove nests humanely

Rats in the walls are unsettling — but they’re also predictable. If you know the signs, you can confirm an infestation early and fix it before serious damage occurs. By controlling food access (yes, even your trash), sealing entry points, and using safe control methods, most homeowners can eliminate wall infestations in weeks.