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How to identify it
- Adults are oval, flat, wingless, about 1/5 inch long, and rusty red or mahogany. Other sources give slightly different sizes: EPA says adults are about the size of an apple seed, 5 to 7 mm (3/16 to 1/4 inch) long, Kentucky says about 3/16 inch, and CDC gives a range of 1 to 7 mm.[1][4][9][3]
- Nymphs look like adults but are smaller (1/20 to 1/5 inch) and lighter, yellowish white. EPA adds that unfed nymphs can be nearly invisible to the naked eye.[1][4][9]
- Eggs are white, about 1/20 inch long, and glued to rough surfaces such as wood or paper near where people sleep; empty eggshells often stay stuck in place after hatching. EPA describes them as pinhead-sized and pearl-white, with an eye spot once they are more than five days old.[1][4][9]
- Signs include small reddish-brown to black fecal spots, blood spots, eggs and light-colored shed skins; heavily infested areas may have a foul or acrid "buggy" smell. Kentucky says the smell is seldom noticeable except in extreme infestations, so it shouldn't be relied on to find bed bugs.[1][9][3]
- Bed bugs can't fly or jump, but they crawl quickly over floors, walls and ceilings.[8][9]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Bat bugs and swallow bugs | Close relatives that look nearly identical; under a hand lens, the hairs on the plate behind the head are longer than the width of the eye, while on bed bugs they are shorter. Managing them means dealing with the bats or birds nesting on the house. Kentucky says that if bat bugs or bird bugs are confirmed, treatment should focus on roosting and nesting sites along with excluding the bats or birds.[1][9] |
| Conenose (kissing) bugs | Larger (up to 3/4 inch), less rounded, and winged as adults.[1] |
Where it lives
Found worldwide wherever people live; the common bed bug is most frequent in northern temperate climates. About 85% of bed bugs are found in or near the bed, and hiding places are usually within about 6 feet of where people sleep or rest.[1]
Biology and life cycle
Females lay 200 to 500 eggs in their lifetimes, usually two to five a day; eggs hatch in about 10 to 15 days at room temperature.[1]
Hatching times differ by source: about 10 to 15 days at room temperature (UC), about a week (Kentucky), or 6 to 10 days (NPIC).[1][9][8]
Nymphs pass through five stages, each needing at least one blood meal; egg to adult takes five weeks to four months depending on temperature and food, fastest between 70 and 82°F. NPIC says it takes about 37 days from egg to adult in ideal conditions, and Kentucky says that at 70 to 80°F with a ready supply of blood they can mature in as little as a month.[1][8][9]
They can go 20 to 400 days without feeding depending on temperature and humidity, and adults may live a year or more. Other sources give shorter typical spans: NPIC says up to about three months without feeding at room temperature and much longer in the cold, and Kentucky says 1 to 4 months is more typical in temperature-controlled buildings but a year or longer is possible at 55°F or less. Kentucky puts the average lifespan at about 10 months.[1][8][9]
They prefer to hide in wood, paper and fabric rather than metal or plastic. EPA says they are only about the width of a credit card, so any crack that will hold a credit card could hide one, and Kentucky says they fit into crevices no wider than a toothpick.[1][5][9]
Bed bugs usually feed every 3 to 7 days. A blood meal takes about 3 to 10 minutes and is painless, and afterward the bug crawls back to a hiding place instead of staying on the person.[8][9]
They spread by hiding in luggage, clothing, bedding, furniture and boxes. NPIC says a single pregnant female can start an infestation, while a male or an immature bug on its own will not. CDC says bed bugs can travel over 100 feet in a night but tend to live within 8 feet of where people sleep.[8][3]
The common bed bug prefers people but will also bite other warm-blooded animals, including dogs, cats, birds and rodents.[9]
Damage and signs
- Common hiding spots: mattress seams and tufts, box spring joints, bed frame cracks, behind headboards and baseboards, under loose wallpaper, behind picture frames, and inside furniture, electronics and upholstery.[1][3][9]
- Bites usually aren't felt when they happen. CDC says most people don't notice bite marks until one to several days later, and in some people they can take as long as 14 days to show up; some people show no signs at all. Bites look like mosquito or flea bites and may be scattered or in a line.[3]
- An infestation has little to do with how clean a home is, although clutter gives bed bugs more places to hide and makes them harder to control.[8][3][9]
Health risk
Bed bugs are not known to spread disease to people. Bites can cause itching and loss of sleep and, rarely, allergic reactions, and intense scratching can lead to a skin infection. A review in JAMA found that although more than 40 human diseases have been blamed on bed bugs, there is little evidence that they spread any of them.[3][10]
Control
Prevention
When traveling, check behind headboards and mattress seams; when you get home, inspect luggage and wash and dry clothes at the hottest settings the fabric allows. Inspect used furniture, especially beds and mattresses, before bringing it inside. Kentucky suggests checking the sheets and mattress seams before unpacking, especially at the pillow end, and putting clothing straight into the washer or dryer when you get home if you had itchy welts during the trip.[1][9]
Sanitation
Vacuum mattress and box spring seams, carpet edges and baseboards, repeating because one pass rarely gets every bug and egg; reduce clutter so there are fewer hiding places. Kentucky says to scrape the end of the wand slowly along seams and edges and to seal the vacuum contents in a trash bag, because bed bugs can survive being vacuumed.[1][9][8]
Traps and physical control
Interceptor cups under bed legs catch bed bugs traveling to the bed; in research they trapped six times more bed bugs than visual searches alone. EPA suggests checking and cleaning interceptors every week.[1][6]
Heat kills all life stages: a dryer on its hottest setting treats clothes and bedding, steam treats mattresses and furniture if it penetrates the hiding spots, and professional room heating aims for at least 140°F for two hours or 130°F for three hours. Holding items at 32°F or below for several days also kills them.[1]
Other sources give different heat and cold targets. Kentucky says a dryer at medium-to-high heat for 10 to 20 minutes kills all life stages, while NPIC says high heat for 30 minutes; Kentucky says professional heat treatments warm the air to about 120 to 130°F. For cold, Kentucky says temperatures below 32°F must be held for one to two weeks, and EPA says items in a sealed bag need three days in a freezer set to 0°F, checked with a thermometer.[9][8][6]
Don't try to cook bed bugs out by turning up the thermostat or running a space heater or fireplace. EPA says this does not work and is dangerous.[6][9]
Bed-bug-proof mattress encasements keep bugs from setting up on the mattress, and bugs sealed inside eventually starve.[1]
Pesticides
Insecticides alone won't control bed bugs. Some bed bug populations have developed resistance to pyrethroids, and NPIC says populations across the country have been found resistant to many common pesticides. NPIC also warns that daily spot treatments can help a resistant population grow, and Kentucky says baits don't work because bed bugs feed only on blood.[1][8][9]
Over-the-counter total-release foggers have been shown to be ineffective against bed bugs and potentially harmful. EPA notes that some foggers are registered for bed bugs, but says they should never be the only method, because the spray does not reach the cracks where bed bugs hide. Kentucky says bleach, alcohol, lighters and foggers should not be used against bed bugs.[1][7][9]
Dusts such as diatomaceous earth and silica gel placed in dry, out-of-the-way spots like wall voids and under baseboards can help as part of an integrated program.[1]
When to call a professional
Confirmed infestations should be managed by trained professionals, who have the most effective products, equipment and follow-up monitoring. Kentucky adds that follow-up visits are usually needed.[1][9]
Why bites alone can't confirm bed bugs
Telling bed bug bites from mosquito, flea or spider bites is difficult to impossible, and people often confuse bed bug welts with mosquito bites.[1]
CDC lists bite marks as one sign but says to look for other clues: shed skins, bed bugs in the folds of mattresses and sheets, and rusty blood spots on mattresses or nearby furniture.[3]
Common questions
- Can I tell bed bug bites from other bites?
- Not reliably. Reactions vary widely and other pests bite too; the only way to confirm bed bugs is to find the bugs or their signs.[1][3]
- Do bug bombs kill bed bugs?
- No. Over-the-counter total-release foggers have been shown to be ineffective against bed bugs and potentially harmful to residents. NPIC says the droplets typically don't get into the hiding spots, and EPA says a fogger should never be your only method.[1][8][7]
- How long can bed bugs live without feeding?
- From 20 to 400 days depending on temperature and humidity; adults have survived over 400 days in the lab at low temperatures. Other sources give shorter typical spans: up to about three months at room temperature (NPIC), or 1 to 4 months in temperature-controlled buildings (Kentucky).[1][8][9]
- Do bed bugs spread disease?
- They are not known to spread disease to people, according to CDC, and a JAMA review found little evidence that they spread any disease.[3][10]
- Does keeping a clean home prevent bed bugs?
- No. Bed bugs feed only on blood, so clean homes can be infested as easily as dirty ones; clutter just gives them more places to hide.[9][8][3]
- Will a clothes dryer kill bed bugs?
- Yes, for anything that can take the heat. Kentucky says 10 to 20 minutes at medium-to-high heat kills all life stages, and NPIC says 30 minutes on high heat.[9][8]
Sources
- University of California Statewide IPM Program, “Pest Notes: Bed Bugs, Publication 7454 (May 2013).” ipm.ucanr.edu/legacy_assets/PDF/PESTNOTES/pnbedbugs.pdf (accessed 2026-11-11)
- iNaturalist, “Cimex lectularius taxon page (order and family).” www.inaturalist.org/taxa/69658 (accessed 2026-11-11)
- U.S. Centers for Disease Control and Prevention, “About Bed Bugs.” www.cdc.gov/bed-bugs/about/index.html (accessed 2026-11-11)
- U.S. Environmental Protection Agency, “Bed Bugs Appearance and Life Cycle.” www.epa.gov/bedbugs/bed-bugs-appearance-and-life-cycle (accessed 2026-11-11)
- U.S. Environmental Protection Agency, “How to Find Bed Bugs.” www.epa.gov/bedbugs/how-find-bed-bugs (accessed 2026-11-11)
- U.S. Environmental Protection Agency, “Do-it-yourself Bed Bug Control.” www.epa.gov/bedbugs/do-it-yourself-bed-bug-control (accessed 2026-11-11)
- U.S. Environmental Protection Agency, “Should I Use a Fogger?.” www.epa.gov/bedbugs/should-i-use-fogger (accessed 2026-11-11)
- National Pesticide Information Center (Oregon State University and EPA), “Bed Bugs.” npic.orst.edu/pest/bedbug.html (accessed 2026-11-11)
- University of Kentucky Entomology, “ENTFACT-636: Bed Bugs (M. F. Potter).” entomology.mgcafe.uky.edu/ef636 (accessed 2026-11-11)
- JAMA, via PubMed, “Goddard and deShazo (2009), Bed bugs (Cimex lectularius) and clinical consequences of their bites, JAMA 301(13):1358-1366.” pubmed.ncbi.nlm.nih.gov/19336711/ (accessed 2026-11-11)