Bed Bugs in Walls: Where They Hide, How to Check and How to Get Rid of Them

TL;DR

• Yes, bed bugs can live in walls. They fit into cracks, gaps behind baseboards, outlets and loose wallpaper, and come out at night to feed.
• Start with the wall behind your bed: baseboards, outlets, switch plates, picture frames, loose wallpaper and the joint where the wall meets the ceiling.
• You rarely see the bugs inside the wall, so look at the openings for dark spots, shed skins, tiny eggs and live bugs.
• Skip sprays and foggers: Purdue University notes they seldom reach bed bug hiding spaces, and they may drive bugs deeper. Bug bombs should not be used against bed bugs (University of Kentucky).
• Steam baseboards and wall cracks slowly, then vacuum daily with a crevice tool. Never steam outlets or switches.
• Need help? Get a quote from a recommended local exterminator through Pest Agent's referral form.

Bed bugs in walls explain a maddening pattern: the mattress gets treated, the sheets get washed, and the bites start again anyway. The survivors were never in the bed. They were a short crawl away, tucked behind the baseboard, the outlet cover or a lifting seam of wallpaper.

Reaching for a fogger or a store-bought spray at that point tends to backfire. The University of Kentucky lists foggers among the things not to use against bed bugs, and pest control companies warn that sprays can drive the bugs deeper into the wall.

A wall gives bed bugs nearly everything a mattress does except a meal, and that meal is only a few steps away once the lights go out.

Can Bed Bugs Live in Walls?

Bed bugs can live in walls: their flat bodies fit into cracks, gaps behind baseboards, outlets and loose wallpaper, and they come out at night to feed. Health Canada lists wallpaper, picture frames and electrical outlets among their hiding places. They use the wall as a shelter between meals, as close to your bed as they can get.

Why Do Bed Bugs Hide in Walls?

Bed bugs hide in walls because a wall next to the bed gives them a dark, tight space a short crawl from their food. According to Health Canada, bed bugs come out at night to feed, attracted by the carbon dioxide you exhale, then crawl back into hiding. The University of Kentucky notes they tend to prefer wood and fabric over metal or plastic, which may be why wooden baseboards, mouldings and frames are favourite spots. Females also lay their sticky eggs in cracks and crevices and behind woodwork (Health Canada). For every hiding place in the home, not just the walls, see our guide on where bed bugs hide.

How Small a Gap Can a Bed Bug Use?

A bed bug can use any gap that would hold a credit card. The US Environmental Protection Agency (EPA) puts it simply: if a crack will hold a credit card, it could hide a bed bug. Adults are about 5 to 7 mm long, the size of an apple seed (EPA), and Health Canada notes they can reach 10 mm. Young bed bugs (nymphs) can be about 1.5 mm long, and eggs are about 1 mm, white and often almost impossible to see on most surfaces (Health Canada). That means hairline cracks in plaster and the seam under a baseboard are big enough.

Can Bed Bugs Climb Walls?

Bed bugs can climb walls. The University of Kentucky says they can crawl rapidly over floors, walls, ceilings and other surfaces. They do have limits: Health Canada notes bed bugs cannot easily climb metal or polished surfaces, and they cannot fly or jump. A bug on your wall walked there.

Can Bed Bugs Travel Through Walls?

Bed bugs travel through walls by crawling through cracks and openings. According to the University of Kentucky, they can move from room to room, or floor to floor, via cracks and openings in walls, floors and ceilings, and they can wander between apartments. Health Canada advises checking entry points on walls you share with neighbours, especially where pipes, wires and other utility lines enter the wall. If you think the bugs are coming from next door, read our guide on bed bugs from neighbours.

How Long Can Bed Bugs Survive in a Wall?

Bed bugs can survive a long time without feeding: Health Canada says from several weeks up to a year and a half. Leaving a room empty for a few weeks will not starve them out. The EPA adds that bed bugs readily travel 5 to 20 feet (about 1.5 to 6 metres) from their hiding places to feed, so bugs in a wall across the room can still reach your bed.

Where Do Bed Bugs Hide in Walls?

Bed bugs hide in the parts of a wall that offer a crack or a covered gap close to where you sleep. Start with the wall behind your bed, then work outward. Here are the spots that Health Canada, the University of Kentucky and the EPA name most often.

Baseboards

Baseboards are one of the most common bed bug hiding spots in walls. The University of Kentucky notes that bed bugs often reside along baseboards, and Health Canada recommends checking the baseboards closest to the bed, paying extra attention to gaps between the baseboard and the wall or floor.

Electrical Outlets

Electrical outlets give bed bugs a covered gap that leads straight into the wall. Health Canada names outlets among their hiding places, and the EPA shows bed bugs gathered along the bottom edge of an outlet.

Switch Plates

Switch plates work like outlets: the gap behind the cover plate is dark and tight. The University of Kentucky lists switch plates with outlets, pictures and mirrors as hiding places on walls.

Picture Frames

Picture frames, mirrors and posters hung near the bed are a classic hiding spot. Health Canada lists picture frames among bed bug hiding places, and the University of Kentucky mentions the space behind wall-mounted pictures and mirrors. Take frames down and check the back, the corners and the hanging hardware.

Wallpaper

Loose or peeling wallpaper creates a pocket bed bugs can crawl under. Health Canada says bed bugs can hide in wallpaper and suggests looking for rips or bumps, and the University of Kentucky names loose wallpaper as a common hiding place.

Where the Wall Meets the Ceiling

The joint where the wall meets the ceiling is a spot bed bugs can use in heavier infestations, according to the EPA and the University of Kentucky. Cracks in wood moulding and trim near the ceiling count too.

Headboards Fixed to the Wall

Headboards fixed to the wall hide bed bugs on both sides: in the headboard and in the wall behind it. The University of Kentucky advises removing wall-mounted headboards so both can be inspected.

Bed bugs can also hide in bathroom walls and fixtures, though this is less common; see our guide on bed bugs in the bathroom.

What Are the Signs of Bed Bugs in Walls?

The signs of bed bugs in walls are dark spots, shed skins, tiny eggs and live bugs around baseboards, outlets and wall hangings. You rarely see the bugs inside the wall itself, so you look for what they leave at the openings.

Dark Spots

Dark spots are the most visible sign of bed bugs in walls. They are bed bug droppings, and the EPA describes them as dark spots that may bleed into fabric like a marker would. On a wall, look for clusters of small black or dark brown dots around outlet covers, along the top edge of baseboards and on the back of picture frames.

Shed Skins

Shed skins are pale yellow, empty bed bug shells left behind as nymphs grow (EPA). You find them in the same cracks and seams where the bugs rest, often mixed with dark spots.

Eggs

Eggs are white, about 1 mm long and almost impossible to see on most surfaces (Health Canada). Females lay them in cracks and crevices and behind woodwork, so you usually need a flashlight held at an angle to spot them along baseboards and moulding.

Live Bed Bugs on the Wall

Live bed bugs on the wall usually mean there are hiding spots nearby. Health Canada notes that if bed bugs are on the walls, they could also be hiding in picture frames, light fixtures and smoke detectors. Adults are brown and flat, and darken to a blood red colour after feeding (Health Canada); nymphs are smaller and lighter in colour.

Bed Bugs in Ceiling Lights

Bed bugs in ceiling lights are a warning sign in apartments and multi-storey homes. Health Canada says bed bugs hiding in ceiling lights could mean they are entering from a room above yours. Tell your landlord or building manager if you see this.

Inspection Tools

Inspection tools for walls are simple: a bright flashlight, a stiff flat card such as an old credit card to slide into gaps (Health Canada), a magnifying glass, and a vacuum with a crevice tool. A screwdriver lets you remove outlet covers and switch plates once the power is off.

Checking Outlets Safely

Checking outlets safely starts with turning off the power. Health Canada advises removing electrical, telephone and cable faceplates to check behind them, and always making sure the power is turned off before opening an electrical outlet. Turn off the breaker for that circuit, unscrew the cover, and look at the back of the plate and the gap around the box with your flashlight. Do not spray liquids or push any product into the electrical box.

Step-by-Step Wall Inspection

A step-by-step wall inspection takes about as long as stripping the bed, and it works best at night or with the lights low.

1. Pull the bed away from the wall so you can reach the wall behind it.
2. Run the flashlight along the baseboards closest to the bed, and slide the card into the gap at the top.
3. Take down picture frames, mirrors and posters near the bed and check their backs.
4. Turn off the power, remove the outlet and switch covers near the bed, and check behind them.
5. Look for rips, bumps or loose edges in wallpaper and check underneath.
6. Check the joint where the wall meets the ceiling, and any wall-mounted headboard.
7. If you find a bug, try to collect it for identification (HealthLink BC).

If the walls are clear but you still have bites, check the bed and furniture next; our guide to signs of a bed bug infestation walks you through it.

How Do You Get Rid of a Bed Bug Infestation in Walls?

A bed bug infestation in walls is hard to treat on your own because the bugs sit in gaps that sprays, steam and vacuums only partly reach. Health Canada strongly recommends hiring a licensed professional pest control operator, and says treatment works best when physical methods and prevention are used together. Here is what you can do yourself, and what to leave to a professional.

Why Sprays and Foggers Backfire

Sprays and foggers backfire on bed bugs in walls because they rarely reach the bugs and can drive them deeper. The University of Kentucky says bug bombs (foggers), bleach, alcohol and cigarette lighters should not be used against bed bugs, NC State Extension adds that foggers are largely ineffective, and Purdue University notes that bed bugs have developed resistance to most classes of pesticides. The Government of Quebec also advises against self-treatment, because insecticides can be unsafe if misused and may increase resistance. If you do buy a product, use only pesticides registered by Health Canada, look for the PCP registration number on the label, and follow the label exactly. Our review of bed bug sprays explains what to look for. Avoid homemade pesticides, and Health Canada also warns against ozone generators.

Vacuuming

Vacuuming removes the bed bugs and eggs you can reach along walls. Health Canada recommends vacuuming daily, including around baseboards and heating units, with a crevice tool for gaps. Seal the used bag in a plastic bag and throw it out in a bin with a lid. Avoid handheld or cloth-bag vacuums, which Health Canada says can become infested.

Steam

Steam kills bed bugs on contact along baseboards, mouldings and wall cracks. Health Canada notes bed bugs die at 50°C and steam cleaners generally emit steam of at least 100°C. Move the nozzle slowly, steam before you vacuum (the steam flushes surviving bugs out of hiding), and avoid excess moisture, which could lead to mould inside the wall. Never steam outlets or switches.

Insecticide Dusts

Insecticide dusts are what professionals use inside wall voids, where liquids cannot go. Professionals typically turn off the power, remove outlet and switch plates, and puff a light layer of dust into the void, never directly into the electrical box. Silica gel dust is one example: the University of Kentucky says it can be very effective when applied correctly, and Texas A&M AgriLife Extension calls silica aerogel a low-toxicity dust, but the powder is light and dusty. This is a job for a licensed professional, not a DIY project, because of the electrical risk and the inhalation risk.

Diatomaceous Earth

Diatomaceous earth is often sold as a natural bed bug killer, but it is a weak choice for walls. The University of Kentucky says it is messy to apply and seldom helps much on its own. The US EPA warns that pool or food grade diatomaceous earth can harm you when you breathe it in. If you use it, choose a product with a PCP number that lists bed bugs on the label, apply a very thin layer only in dry cracks along baseboards, and keep it away from children and pets.

Heat Treatment

Heat treatment raises the temperature of a room high enough to kill bed bugs in all hiding places, including wall gaps. The University of Kentucky says professionals use heaters and fans to bring the air to about 120 to 130°F (about 49 to 54°C) wherever bugs may be present. Health Canada says heat treatments should be left to the professionals, and the EPA warns that turning up the thermostat or using space heaters won't do the job. Learn how it works in our guide to bed bug heat treatment.

When to Call a Pest Control Professional

Calling a pest control professional is the right move as soon as you confirm bed bugs in your walls. HealthLink BC recommends qualified professionals for chemical treatments and notes that multiple applications will likely be necessary, and the University of Kentucky says follow-ups are usually needed. Health Canada suggests finding an operator through the Canadian Pest Management Association or your provincial pest management association. To know what to expect, read what exterminators do for bed bugs. You can also get a quote from a recommended local exterminator through Pest Agent's referral form.

What to Do in an Apartment

In an apartment, tell your landlord right away (Health Canada). Bed bugs can wander between units, so the University of Kentucky stresses that units next to an infested one should be inspected too, and HealthLink BC notes building owners should check municipal bylaws before trying self-treatment. Our guide on bed bugs in apartments covers your next steps.

How Do You Keep Bed Bugs Out of Your Walls?

Keeping bed bugs out of your walls means closing the cracks and gaps they hide in and checking the openings they use to move between rooms. Do this after treatment, or as prevention, not while a professional is treating, so you follow their instructions first.

Sealing Cracks

Sealing cracks removes hiding spots. Health Canada recommends sealing all cracks and crevices on wooden bed frames, between baseboards and in walls, ceilings, windows and door frames. Use caulk along the top of baseboards and around trim.

Repairing Wallpaper

Repairing wallpaper closes the pockets bed bugs crawl into. Health Canada and HealthLink BC both advise repairing or removing peeling or loose wallpaper and decorative borders.

Tightening Faceplates

Tightening faceplates on outlets and switches closes the gap around the cover. Health Canada and HealthLink BC both recommend tightening loose electrical faceplates.

Shared Walls

Shared walls are the main route between units in a building. Health Canada recommends checking every entry point on walls you share with neighbours, including openings where pipes, wires and other utility lines enter the wall, and sealing them.

Interceptors

Interceptors are small plastic dishes placed under bed legs that catch bed bugs crawling up from the floor and help you detect them early (University of Kentucky). A trap under each bed leg also creates a barrier between the floor and the bed. Move the bed a little away from the wall so the bugs cannot climb straight from the wall onto it. The bed bug hub lists every guide, including prevention.