The essentials in 30 seconds
The common bed bug (Cimex lectularius) is a flat, wingless, reddish-brown insect. Adults are 5 to 7 mm long, about the size of an apple seed, and feed on blood at night. The surest signs are dark spots the size of a full stop on mattress seams, rusty stains on sheets, pale eggs about 1 mm long and the bugs themselves; itchy bites in a line or cluster are a clue, but bites alone prove nothing. Wash bedding at 60 °C, tumble dry on a hot setting for at least 30 minutes, vacuum thoroughly and fit a bed bug-proof mattress cover. A complete clear-out usually needs a pest control professional, and checks for a year afterwards.
- Bag bedding, clothes and small items inside the room before carrying them anywhere: bed bugs travel on belongings.
- Wrap a mattress in plastic before taking it out of the house.
- Skip foggers and bug bombs: they fail against bed bugs and can harm the people living there.
What bed bugs look like: size, color and baby bed bugs
Bed bugs go through seven stages: the egg, five nymph stages and the adult. Each nymph needs a blood meal to grow to the next stage, so you can find several sizes at once in an active infestation.
| Stage | Size | What you see |
|---|---|---|
| Egg | About 1 mm, a pinhead | Pale, pearly, glued in seams and cracks |
| Young nymph (baby bed bug) | 1.5 to 2.5 mm | Almost translucent; turns red after feeding |
| Older nymph | 3 to 4.5 mm | Light brown, like a small adult |
| Adult | 5 to 7 mm, an apple seed | Flat, oval, reddish-brown; swollen and darker after feeding |
| Insect | How to tell it apart | Where it shows up |
|---|---|---|
| Bed bug | Flat, oval, wingless, reddish-brown, crawls slowly | Mattress seams, bed frame, headboard |
| Flea | Tiny, dark, narrow from side to side, jumps | Pet beds, carpets, sofas; bites on the lower legs |
| Carpet beetle larva | Hairy, striped, caterpillar-like | Carpets, wardrobes, under furniture; see our carpet beetle guide |
| Young cockroach | Long legs and antennae, runs fast | Kitchens and bathrooms; see our cockroach guide |
Can you see bed bugs with the naked eye? Yes, adults and groups of nymphs, but not easily. Adults are reddish-brown, flat and oval, about 5 to 7 mm long (the EPA's traveler leaflet puts them at 1/4 to 3/8 inch), and turn balloon-like and more elongated after a meal. Baby bed bugs (nymphs) are translucent or whitish-yellow and, if they have not fed recently, can be nearly invisible because of their color and size. Eggs need a magnifying glass. Bed bugs do not jump or fly: they crawl, and travel on luggage and furniture.
What bed bug bites look like and what to do
Bed bug bites are raised and itchy, often in a line or a small group, on skin left uncovered in bed: face, neck, arms, hands and legs. On white skin they usually look red or pink; on black or brown skin they can look brown, red or purple and be harder to see. Most people notice them one to several days after the bite, and in some people marks take up to 14 days to appear. Some people show no reaction at all, which is why one partner may be bitten and the other seems untouched.
| Bites | Typical pattern | Where on the body |
|---|---|---|
| Bed bugs | Raised, itchy, in lines or clusters, found on waking | Skin exposed during sleep: face, neck, arms |
| Fleas | Large, red, raised groups | Usually below the knees |
| Mosquitoes | Small, raised and itchy, scattered | Any uncovered skin, often after an evening outdoors |
What helps, following NHS advice:
- Hold a clean, cool, damp cloth on the bites to ease itching and swelling.
- Keep the skin clean and leave the bites alone to lower the risk of infection.
- Ask a pharmacist about a mild steroid cream such as hydrocortisone; children under 10 and pregnant women should check with a doctor first.
- An antihistamine can help if the itching keeps you awake.
- See a GP if the bites stay very painful, swollen or itchy after pharmacy treatment, or if redness and swelling spread, as they may be infected.
Bed bugs are not known to spread disease. Their real cost is itching, broken sleep and worry, so confirming the cause quickly is worth it.
Signs of bed bugs on a mattress and in the bedroom
- Dark spots (bed bug poop) about the size of a full stop on mattress seams, the bed base and the headboard. They are droppings and smear like a marker pen if you wipe them with a damp cloth.
- Rusty or reddish stains on sheets and pillowcases, from bugs crushed as you sleep.
- Eggs and eggshells: tiny, pale yellow, about 1 mm, in seams and cracks.
- Shed skins: amber, empty shells left as nymphs grow.
- A sweetish, musty smell in heavy infestations.
- Live bugs: flat and brown, slow to run, hiding in cracks when disturbed.
What attracts bed bugs and how an infestation starts
Bed bugs find people by the carbon dioxide, warmth and moisture we give off, which is why they settle close to beds and sofas. An infestation usually starts with bugs carried in on luggage, clothing or second-hand furniture; second-hand mattresses and furniture are known high-risk sources.
How to check for bed bugs, step by step
Allow about 20 to 30 minutes for a first check of the bed. A bright torch, a credit card, a magnifying glass and a roll of tape make it easier.
-
01
Strip the bed
Remove the sheets one at a time over the bed and look at each corner and seam before bagging them for the wash.
-
02
Work along the mattress seams
Run the torch slowly along the piping, seams, tags and handles. Slide the edge of a credit card into the folds to push out any bugs or eggs.
-
03
Check the underside
Lift the mattress and look at the base, the divan fabric, the corners and the joints of the frame.
-
04
Look at the headboard
Check where it meets the wall, around screws and in any cracks. If it comes off easily, take it off.
-
05
Move out from the bed
Bedside tables (inside drawers and joints), skirting boards, sockets, picture frames and curtain folds.
-
06
Test the spots
Wipe a dark spot with a damp tissue: bed bug droppings smear rust-brown.
-
07
Photograph and record
Take photos of anything you find, with a coin for scale, and note which rooms you checked.
-
08
Set interceptors
Put bed bug interceptor cups under the bed legs and check them weekly. They catch bugs walking to and from the bed and help confirm an infestation.
Where bed bugs hide
| Area | What to look for |
|---|---|
| Mattress | Seams, piping, labels and handles |
| Bed base and divan | Fabric underneath, corners, joints in the frame |
| Headboard | Where it meets the wall, screws, cracks |
| Bedside tables | Inside drawers and joints |
| Walls | Skirting boards, sockets, picture frames, loose wallpaper, where wall meets ceiling |
| Sofa | Seams, between and under cushions, the frame underneath |
| Luggage | Seams and pockets of suitcases used on trips |
Bed bugs usually stay within about 2.5 metres of where people sleep, although they can crawl much further in a night to reach a new host. Any crack that would hold a credit card can hold an adult.
What to do in the first 24 hours
-
01
Confirm the infestation
Use the mattress check above and keep photos to show a professional.
-
02
Keep things in the room
Carry bedding, clothes or furniture to other rooms only sealed in bags. Bed bugs travel on belongings and can also crawl into nearby rooms, so moving to another bedroom does not leave them behind.
-
03
Bag the bedding
Put sheets, covers and worn clothes into sealed bags inside the room and take them straight to the washing machine.
-
04
Wash hot and tumble dry
Wash everything that tolerates it at 60 °C, then tumble dry on a hot setting for at least 30 minutes.
-
05
Freeze what you cannot wash
Small items can go into a sealed bag in the freezer for two to three weeks.
-
06
Vacuum thoroughly
Mattress, bed base, skirting boards and carpets. Seal the bag or empty the canister into a sealed bag and put it in an outdoor bin.
-
07
Fit an encasement
A zipped mattress cover certified for bed bugs traps any that remain and makes checking easier.
-
08
Reduce clutter
Clear the space under the bed, keep bedding off the floor and pull the bed a few centimetres away from the wall.
-
09
Call a professional
Ask for an inspection and treatment plan. The most effective approach combines heat or steam with professional-use insecticides.
What kills bed bugs
Heat is the most reliable weapon, provided it reaches every stage, eggs included. Bed bugs die at about 45 °C given enough time; the higher the temperature, the shorter the exposure needed.
| Method | What works | Limits |
|---|---|---|
| Hot wash and tumble dryer | 60 °C wash, then a hot dryer for at least 30 minutes | Only for washable textiles |
| Steam | At least 54 °C at the surface, with a diffuser so the jet does not scatter the bugs | Slow; seams and cracks one by one |
| Freezing | Sealed bag in the freezer for two to three weeks; the freezer must reach −18 °C, so check it with a thermometer | Only items that fit; many home freezers run warmer |
| Professional heat treatment | The whole room held at about 60 °C for 2 hours or 54 °C for 3 hours | Specialist equipment and training |
| Professional-use insecticides | Targeted application to cracks and furniture | Often needs repeating; trained technician |
| Diatomaceous earth or silica dust | A thin film in dry voids and under skirting boards | Slow, weeks to months; useless once damp |
| Household sprays and foggers | Kill on contact at best | Poor results; can scatter the bugs |
Turning up the central heating or using a heater in the room only warms the bugs: it never reaches lethal temperatures in cracks and creates a fire risk.
How long bed bugs live and how fast they spread
| Fact | Figure |
|---|---|
| Adult lifespan | A year or more |
| Generations | Up to four a year |
| Egg to adult | About 5 weeks to 4 months, depending on temperature and food |
| Eggs | 200 to 500 per female over her life, usually 2 to 5 a day |
| Time without feeding | 20 to 400 days, depending on temperature and humidity |
| Feeding | 3 to 10 minutes per meal; adults may feed every 5 to 7 days |
That long survival without a meal is why an empty room, a holiday away or a stored sofa rarely starves them out.
How to check a hotel room for bed bugs
-
01
Keep the case closed at first
Leave your luggage on a hard surface, away from the bed, until you have checked the room.
-
02
Check the luggage rack
Look along the straps and joints before using it.
-
03
Pull back the sheets
Check the corners of the mattress, the seams, tufts and tags with your phone torch.
-
04
Look behind the headboard
It is often fixed to the wall; shine the torch into the gap.
-
05
Check upholstered chairs
Seams and under cushions.
-
06
Ask for another room if you find signs
Photograph what you find and ask the hotel for a room change, or move hotel.
-
07
Unpack outside the bedroom at home
Inspect the suitcase in the hall or garage, wash travel clothes on the hottest setting the fabric allows and tumble dry them, then store the case away from bedrooms.
How to avoid bringing them home
- Check second-hand beds, sofas and bedside tables with a torch before bringing them indoors.
- Use shared laundries with care: carry clean clothes home in a new plastic bag.
- In flats, tell the building manager or neighbours: bed bugs can move between homes.
- After a treatment, keep interceptors under the bed legs as an early-warning system.
How long it takes to get rid of bed bugs
Clearing bed bugs can take weeks to months, depending on how big the infestation is, and treatments may need repeating to catch bugs that hatch from eggs later. Check the bed, the interceptors and nearby furniture at least every 7 days, and keep checking for at least a year after you finish. Items you cannot treat can stay sealed in a bag for up to a year.
Mistakes that spread an infestation
- Setting off foggers or spraying products everywhere.
- Moving furniture to other rooms or flats.
- Dumping the mattress without wrapping it.
- Sleeping on the sofa: the bugs follow you there.
- Stopping treatment when the bites ease: eggs hatch later.
- Using flammable liquids such as alcohol or petrol: they are dangerous and do not solve the problem.
Bed bugs: frequently asked questions
What do baby bed bugs look like?
Nymphs are smaller versions of the adult, translucent or whitish-yellow, and turn red after feeding. The youngest are about 1.5 mm long.
What does bed bug poop look like?
Dark spots about the size of a full stop on mattress seams, the bed frame and sheets. They are dried droppings and smear like a marker pen if you wipe them with a damp tissue.
Can bed bugs jump?
No. Bed bugs cannot jump or fly; they crawl and spread by hitching a ride on belongings.
What kills bed bugs instantly?
Nothing kills a whole infestation instantly. Heat kills bed bugs on contact: temperatures of 55 °C (131 °F) or above are lethal to all stages. Avoid rubbing alcohol, kerosene and petrol: the EPA warns they can harm you and catch fire.
What do bed bug bites look like?
Raised, itchy bumps, often in a line or small group, on skin exposed while you sleep. They look red or pink on white skin and brown, red or purple on darker skin.
How do I check for bed bugs?
Strip the bed and run a torch along the mattress seams, tags and piping, then the bed frame and headboard. Look for dark spots, rusty stains, pale eggs, shed skins and live bugs.
Where do bed bugs come from?
They hitch a ride on luggage, clothing, bedding, second-hand furniture and boxes. Hotels, holiday lets and shared buildings are common sources; cleanliness has little to do with it.
Do bed bugs spread disease?
They are not known to spread disease. Scratching the bites can lead to a skin infection, and the itching can disturb sleep.
What kills bed bugs?
Heat: a 60 °C wash with at least 30 minutes in a hot dryer for textiles, and professional heat treatment for rooms. Freezing at −18 °C works for small items.
How long do bed bugs live?
Adults can live a year or more and survive for months between meals, from 20 to 400 days depending on conditions.
Can bed bugs fly?
They are wingless, so they crawl. They move from home to home on belongings and through gaps between flats.
Do I need to throw away my mattress?
Usually not. With professional treatment and an encasement you can keep it. If you do get rid of it, wrap it in plastic first.
Sources
Official health and pest control guidance, checked on 26 October 2026.
- NHS · Bedbugs ↗Signs, how bites look on different skin tones, treating bites, when to see a GP, 60 °C wash and 30-minute tumble dry, freezing for two to three weeks.
- NHS · Insect bites and stings ↗How flea and mosquito bites look, and the signs of a serious allergic reaction.
- CDC · About bed bugs ↗Size, bites appearing after one to 14 days, no known disease transmission, hiding places and distance from the bed.
- US EPA · How to find bed bugs ↗Dark spots, rusty stains, eggs and where to look.
- US EPA · Bed bugs: appearance and life cycle ↗Sizes of eggs, nymphs and adults; adults reddish-brown and balloon-like after feeding, nymphs translucent or whitish-yellow and nearly invisible unfed (checked again on 2 November 2026).
- US EPA · Bed bugs: a traveler's guide (PDF) ↗Adults 1/4 to 3/8 inch; bed bugs do not jump or fly (checked on 2 November 2026).
- US EPA · Do-it-yourself bed bug control ↗Encasements, interceptors, steam, freezing at −18 °C, warnings about foggers and heaters, and how long treatment and follow-up checks take.
- University of California IPM · Bed bugs ↗Life cycle, survival without feeding, lethal temperatures, interceptors, dusts and travel tips; adults and groups of nymphs visible to the naked eye, eggs with a magnifier; dried droppings; second-hand mattresses and furniture as high-risk sources (checked again on 2 November 2026).
- Penn State Extension · Biology, habitat and management of bed bugs ↗Bed bugs crawl to nearby rooms and flats and spread on bedding, furniture and other belongings; they locate hosts by carbon dioxide, warmth and moisture; 131 °F or above is lethal to all stages (checked again on 2 November 2026).
- Real Decreto 1054/2002, biocides (BOE, Spain) ↗Article 27: register of pest control companies (ROESB).
- Real Decreto 830/2010, training for biocide treatments (BOE, Spain) ↗Training required for professional-use products.
Found bed bugs?
Take photos of the signs and note which rooms are affected before you book an inspection.