UV Light and Bed Bugs
Under Black Light & UV Light?
UV Detection · Black Light · Bed Bug Colour · UV Devices · Professional Inspection
The Complete Homeowner Reference — 2025 / 2026 Edition
Bed bugs are difficult to detect with the naked eye. Their flat, reddish-brown bodies let them hide deep in mattress seams, baseboards, and furniture joints. UV and blacklight tools are increasingly marketed as detection aids, but do they work? UV lights can help spot traces such as shed skins and excrement, but they are not reliable for confirming infestations. This guide explains what UV and black light reveal about bed bugs, what colour bed bugs appear under UV light, whether specific UV devices like the Lumivyx HaloClean are effective, and which professional-grade detection methods work best.
Do Bed Bugs Show Up Under Black Light?
This is one of the most common questions about bed bug detection. The short answer is: partially. Bed bugs themselves do not fluoresce brightly under UV or black light. However, the traces they leave behind—shed skins, egg casings, and especially dried excrement—exhibit a faint fluorescence that can make them slightly easier to spot under UV illumination in a darkened room. (Bed Bug Foundation – Identification, n.d.)
What Exactly Happens Under a Black Light?
- Live bed bugs: Appear slightly luminescent in some cases due to their natural chitin exoskeleton, but do not glow brightly. The fluorescence is subtle and inconsistent — not the dramatic glow seen in marketing photographs. (Thompson, 2026)
- Bed bug excrement (dark spots): Dried faecal matter may appear slightly highlighted under UV, though it does not fluoresce as vividly as biological fluids such as urine. (Wilson & Miller, 2022)
- Shed skins (exuviae): The translucent, empty shells left behind after moulting can sometimes appear faintly luminous under UV light, making them slightly more visible against dark fabrics. (Iten, 2025)
- Eggs: Tiny, white, about 1 mm long. Bed bug eggs do not fluoresce significantly under standard UV, but their white colour can make them slightly more visible when UV light creates contrast against surrounding surfaces. (Bed Bug Workshop, 2024)
- Blood stains: Dried blood may exhibit very slight fluorescence under UV, though not as pronounced as that of fresh biological material. (Qu et al., 2023, pp. 27549-27557)
ℹ️ UV and black light alone are not a reliable standalone method for confirming a bed bug infestation. They can assist in identifying areas of suspected activity, but a confirmed identification requires physically finding a live or dead bed bug.
UV Light for Bed Bugs — How It Works
UV (ultraviolet) light occupies a portion of the electromagnetic spectrum just beyond the visible range of human vision, with wavelengths typically between 10 and 400 nanometres. Black lights are a specific type of UV lamp that emits primarily in the UVA range (315–400 nm) while filtering out most visible light. (Ultraviolet Radiation-Fact Sheet, 2017)
The Science of UV Detection
When UV light strikes certain organic compounds, it causes those compounds to fluoresce — meaning they absorb the UV energy and re-emit it as visible light at a longer wavelength. This is why urine stains, laundry residues, and some biological materials glow under black light. (Ohio BCI Laboratory, 2025)
Bed bugs are partially made of chitin — the same protein-based material that forms insect exoskeletons broadly. Chitin does exhibit some degree of fluorescence under UV light, which is the basis for claims that black lights can detect bed bugs. (Reinhardt et al., 2017, pp. 56-62) However, the fluorescence of chitin in bed bugs is:
- Weak — not a dramatic glow, more of a faint sheen
- Inconsistent — varies based on the age of the bug, its feeding state, and the wavelength of UV used.
- Non-specific — many other insects and organic materials fluoresce similarly.
UV Wavelengths and Effectiveness
UV Type | Wavelength | Effectiveness for Bed Bugs | Safety |
| UVA (black light) | 315 – 400 nm | Mild fluorescence of chitin and some stains | Safe for brief home use |
| UVB | 280 – 315 nm | Not used for detection | Hazardous — avoid |
| UVC (germicidal) | 100 – 280 nm | Used in sanitising devices — not for detection | Very hazardous — never expose skin or eyes |
| 395 nm UV LED | ~395 nm | Most common wavelength in consumer detection UV lights | Safe with normal precautions |
| 365 nm UV LED | ~365 nm | Stronger fluorescence response; better for stain detection | Use UV-rated glasses |
💡 For bed bug detection purposes, a 365–395 nm UVA black light is the appropriate choice. UVC devices marketed for ‘killing’ bed bugs operate on a completely different principle and are not detection tools.
Table 1. Comparison of UVA and UVC Devices for Bed Bug Detection and Control
Feature | UVA Black Light (365–395 nm) | UVC Device (200–280 nm) |
Intended Use | Detection of traces (exuviae, faecal spots) | Germicidal disinfection; insect harm at close range |
Wavelength | 365 – 395 nm | 200 – 280 nm |
Ability to Detect Bed Bugs | Provides subtle fluorescence to organic material; aids visual inspection | Does not assist in detection |
Ability to Kill Bed Bugs | Ineffective | Only effective with direct, sustained exposure; cannot reach hidden bugs |
Safety Concerns | Generally safe with normal precautions | Hazardous to skin and eyes; strict safety measures required |
This comparison highlights that only UVA black lights are suitable for supplemental bed bug detection, whereas UVC devices are not appropriate for this purpose and pose significant safety risks.
When selecting a UV flashlight for bed bug inspection, look for these key features:
– Wavelength: Choose a UVA black light with a wavelength between 365 nm and 395 nm for best results.
– Brightness: Opt for a light with at least a 3-watt LED output to ensure sufficient intensity for illuminating faint traces.
– Safety: Select a device that comes with safety information and preferably includes, or recommends, UV-filtering safety glasses to protect your eyes. Avoid using UV-C devices for inspection, as they pose safety risks and do not improve detection.
– Beam Focus: A flashlight with an adjustable or narrow focus beam helps highlight specific areas such as seams and crevices.
– Durability: Look for a sturdy, well-built housing to handle regular inspection use.
These features ensure you choose a UV light that is both effective and safe for home bed bug inspections.
What Colour Are Bed Bugs Under UV Light?
Understanding what you are looking for under UV light is critical. Otherwise, the exercise is more likely to confuse than provide useful information.
Bed Bug Colour Under Normal Light
Under standard white light, bed bugs appear:
- Reddish-brown to mahogany brown when unfed.
- Bright red to deep red immediately after a blood meal
- Translucent tan or pale yellow as newly hatched nymphs
- Flattened, oval-shaped, approximately 4–5 mm long as adults (roughly the size of an apple seed)
What Colour Are Bed Bugs Under UV Light?
Under UV or black light illumination in a darkened room, bed bugs may appear:
Bed Bug Stage | Colour Under Normal Light | Appearance Under UV Light |
| Adult (unfed) | Reddish-brown | Faint pale blue-white sheen or very slight luminescence — not dramatic |
| Adult (recently fed) | Dark red to black | Minimal change — darker colouration absorbs UV |
| Nymph (young) | Pale tan / translucent | Slightly more visible; translucent body catches UV |
| Egg | Pearly white | Minimal fluorescence — white colour remains white |
| Shed skin (exuviae) | Pale tan / clear | Faint glow — translucent shells catch UV light slightly |
| Dried excrement | Dark brown to black spots | May appear very slightly highlighted; not dramatic |
⚠️ Bed bugs do NOT glow bright green, blue, or white under UV light in the way that is often depicted in online videos and marketing images. Those results are typically staged, edited, or use extreme UV intensities not available in consumer products.
What Does Glow Brightly Under Black Light (That Is Not Bed Bugs)
A key challenge with using black lights for bed bug inspection is that many other common household substances fluoresce more dramatically than bed bugs, leading to confusion and false positives:
- Pet urine — glows very brightly (yellow-green); one of the strongest household fluorescers
- Human urine — similar bright glow
- Laundry detergent residue — many detergents contain optical brighteners that fluoresce strongly in a blue-white hue.
- White fabric and paper — optical brightening agents added during manufacturing cause strong blue-white fluorescence.
- Toothpaste, some lotions, and cosmetics — fluoresce white to blue
- Some adhesives and tapes — fluoresce under UV
- Lint, dust, and general organic debris — mild, diffuse fluorescence
💡 If something glows very brightly blue-white under your black light, it is almost certainly laundry detergent residue or optical brightener on fabric — not bed bug evidence.
What Does UV Light Reveal That the Naked Eye Cannot?
Despite UV’s limitations for direct bed bug detection, there are situations where UV light adds value to a bed bug inspection.
Useful Applications of UV Light in Bed Bug Inspection
ℹ️ UV light serves primarily as a supplementary search tool, most effective for highlighting areas that may warrant further investigation. Its main value lies in screening for potential signs of bed bug activity, such as faint fluorescence from shed skins or excrement, which may not be readily visible under ambient lighting. However, UV light should not replace a systematic physical inspection using a magnifying glass and bright white light, tools that remain essential for the direct identification of bed bugs, eggs, or cast skins. Thus, UV detection is best utilized in combination with traditional inspection methods to improve overall detection accuracy.n.
Are Bed Bugs Attracted to or Scared of Light?
Understanding bed bug behaviour in relation to light is important for both detection and prevention strategies.
Are Bed Bugs Attracted to UV Light?
No — bed bugs are not attracted to UV light. Unlike many insects, such as moths and beetles, bed bugs do not navigate toward or respond positively to ultraviolet light. Their sensory world is primarily driven by:
- Carbon dioxide (CO2) — exhaled by sleeping humans; the primary attractant
- Body heat — infrared warmth of a nearby warm-blooded host
- Chemical signals (kairomones) — body chemicals emitted by humans and other warm-blooded hosts
- Vibration — movement cues that indicate a potential host is nearby
Are Bed Bugs Scared of Light?
Bed bugs are described as photophobic — they actively avoid light and prefer darkness. This is why they feed at night and retreat into dark crevices during daylight hours (Romero et al., 2010, pp. 1516-1522)s. Key behavioural facts:
- Bed bugs strongly prefer darkness and retreat from bright light.
- Turning on a light when you suspect an infestation will cause bed bugs to move toward cover, making them harder to find.
- Bed bugs are NOT driven away permanently by light — they wait in darkness until conditions are suitable again.
- Keeping a light on does not prevent bed bug feeding — a hungry bed bug will feed even in partial light if the host is accessible.
⚠️ Some sources suggest ‘sleeping with the light on’ to prevent bed bug bites. This is not an effective strategy. Bed bugs can and do feed in lighted rooms, and this approach will not address an infestation.
Are Bed Bugs Attracted to White Light?
No. Bed bugs show no positive attraction. Bed bugs show no attraction to any wavelength of visible light. White, LED, and UV light are not attractants. However, using bright white light improves your ability to see bed bugs during an inspection. White light paired with UV is the most effective combination for a manual inspection.
Best UV Light for Finding Bed Bugs
Not all UV lights are equally useful for bed bug inspection. The wavelength, intensity, and beam pattern affect how useful a UV light will be for this purpose.
What to Look for in a UV Light for Bed Bug Detection
Feature | Recommended Specification | Why It Matters |
| Wavelength | 365 nm or 395 nm UVA | 365 nm gives stronger fluorescence; 395 nm is more widely available |
| Power / intensity | 3W LED or higher | Higher intensity increases the visibility of subtle fluorescence |
| Beam type | Focused or narrow beam | Concentrated beam for crevices; wide beam for large areas |
| LED count | 9 LEDs or more | More LEDs = greater area coverage per pass |
| Form factor | Handheld torch (flashlight) style | Allows directed inspection of seams and joints |
| UV glasses included | Yes — UV-filtering glasses | Protect eyes during extended use; also improve contrast |
UV Light Wavelength Comparison for Bed Bug Inspection
Wavelength | Fluorescence Strength | Best For | Consumer Availability |
| 395 nm | Moderate | General home inspection; broad surface scanning | Very widely available — most consumer UV torches |
| 385 nm | Moderate–strong | Better stain detection; slightly more sensitive | Available from specialist suppliers |
| 365 nm | Strong | Best fluorescence detection; preferred by professionals | Available; higher cost than 395 nm |
| Under 365 nm | Very strong | Professional and laboratory use | Not widely available to consumers; handle with care |
💡 A 365 nm UV flashlight paired with UV-filtering glasses (which filter out the UV while allowing fluorescence to be seen more clearly) is the most effective consumer option for bed bug trace detection.
Lumivyx HaloClean UV — Does It Work for Bed Bugs?
The Lumivyx HaloClean is a UV-C sanitising device marketed for home hygiene and pest-related applications. It is important to understand exactly what it does and does not do regarding bed bugs.
What Is the Lumivyx HaloClean?
The Lumivyx HaloClean is a UV-C germicidal device that emits UV light in the 200–280 nm range, known to be effective at damaging the DNA of bacteria, viruses, and some fungi. UV-C energy at sufficient intensity and exposure time can also harm insects, including bed bugs, at close range.
Does the Lumivyx HaloClean Work for Bed Bugs?
Claim | Accuracy | Explanation |
| Kills bed bugs on direct contact | Partially — limited conditions | UV-C can damage bed bugs at very close range with extended exposure; it cannot penetrate hiding spots, mattress interiors, or baseboards where bed bugs live |
| Sanitises surfaces | Yes — for bacteria/viruses | This is its primary, well-documented function |
| Detects bed bugs | No | The Lumivyx HaloClean is a sanitising device, not a detection tool |
| Eliminates an infestation | No | Cannot reach hidden bed bugs; cannot treat inside mattresses, wall voids, or furniture joints where populations live |
| Works as a UV black light for detection | No | UV-C is a different wavelength from the UVA used in black lights; it is not designed for fluorescence detection |
⚠️ UV-C light is hazardous to human skin and eyes. Never look directly at a UV-C device while it is operating, and never expose unprotected skin to UV-C light. Always follow manufacturer safety instructions precisely. When using any UV device, wear appropriate protective gear, such as UV-blocking safety glasses and protective gloves, and cover exposed skin. Limit exposure duration and operate UV-C devices only in unoccupied rooms to minimise risk. UVA black lights used for detection should also be handled with care: avoid staring directly at the light or directing it toward eyes, and use the light for brief inspection periods only.
Is the Lumivyx HaloClean Worth Using for Bed Bugs?
The Lumivyx HaloClean is a useful household sanitising tool for reducing surface bacteria and viruses. However, as a bed bug treatment or detection device, its effectiveness is severely limited by:
- Inability to penetrate the hiding spots where bed bugs actually live — inside mattress seams, wall cracks, furniture joints, and baseboards
- UV-C light kills only what it directly illuminates at close range; bed bugs that are 1 inch away behind fabric or wood are not affected
- It provides no detection capability — it does not help you find where bed bugs are located.
- A confirmed bed bug infestation requires heat treatment, chemical pesticide treatment, or professional extermination — UV-C sanitising devices are not a substitute.
ℹ️ If you have a confirmed bed bug infestation, consult a licensed pest management professional. Pest control authorities do not recognise UV-C devices alone as an effective treatment method.
How to Use a UV or Black Light to Inspect for Bed Bugs
UV light inspection is most useful as part of a systematic, methodical examination of an area, not as a standalone tool. Here is a step-by-step approach to maximise what a UV light can tell you. A UV torch (black light) — 365 nm or 395 nm UVA, minimum 3W LED
- UV-filtering safety glasses
- A bright white flashlight (for direct physical inspection after UV scanning)
- A magnifying glass (at least 10×)
- Latex or nitrile gloves
- A notepad or phone to photograph and record areas of concern
Step-by-Step UV Inspection Method
- Prepare the room — remove bedding and strip the mattress to the bare fabric. Set bedding aside for inspection.
- Darken the room — UV fluorescence is most visible in a fully darkened room. Close curtains and turn off all other lights.
- Start at the mattress — hold the UV light 6–12 inches from the mattress surface and work slowly across every seam, tufting button, and fabric fold. Move the light at about one foot per second.
- Inspect the box spring — this is one of the most common hiding locations. Examine every corner, staple point, and fabric edge.
- Inspect the bed frame — check all joints, screw holes, and hollow sections of the frame.
- Inspect the headboard — examine every groove, crack, and upholstered section.
- Inspect the surrounding floor area — baseboards, carpet edges, and floor cracks within 10–15 feet of the bed.
- Note any areas with unusual fluorescence — mark with a sticky note and follow up with white light and a magnifying glass.
- Confirm physically — any suspected area must be examined under bright white light with a magnifying glass. Only a physically observed bug, egg, cast skin, or confirmed faecal spotting constitutes evidence.
What to Look for During UV Inspection
What You See Under UV | Likely Explanation | Action |
| Scattered bright white glow on fabric | Laundry detergent residue or optical brighteners | Not bed bugs — no action needed |
| Bright yellow-green glow | Pet or human urine | Not bed bugs — clean area |
| Faint blue-white smear or sheen in mattress seams | Possible exuviae or excrement build-up | Inspect with white light and magnifying glass |
| Small bright white specks in a cluster | May be eggs, lint, or debris | Inspect closely with white light |
| Scattered dark spots with faint edge glow | Dried excrement or blood spots | High priority — inspect immediately with white light |
| Moving spot in UV beam | Live insect — possibly bed bug | Do not lose sight of it; capture for identification |
Other Light-Based Detection Methods
UV and black light are not the only light tools used for bed bug detection. Several other approaches offer advantages in certain situations.
Bright White LED Flashlight
A simple, bright white LED flashlight remains the single most effective light tool for physically spotting live bed bugs, cast skins, and eggs. Bed bugs’ reddish-brown colouration is easiest to identify under white light. Professional pest inspectors typically rely on a high-powered white LED torch as their primary visual tool, supplemented by other methods.
Thermal / Infrared Imaging
Bed bugs generate slight heat, and large infestations can create detectable thermal signatures. Thermal imaging cameras, though expensive, allow pest professionals to identify heat signatures behind walls, inside furniture, and in areas not accessible to standard inspection. This is a professional-grade tool not available to most homeowners.
CO2 and Heat Lure Traps
These devices emit carbon dioxide and sometimes heat to mimic a human host, attracting bed bugs out of hiding and into a trap. While not strictly a ‘light’ method, they are often used alongside visual inspection to draw bed bugs into a detectable position. Interceptor cups placed under bed legs serve a similar passive trapping function.
Comparison of Detection Methods
Detection Method | Effectiveness | DIY Feasible? | Cost Range |
| Bright white flashlight + physical inspection | High — best DIY method | Yes | $10 – $40 |
| UV / black light (395 nm) | Moderate — supplementary use only | Yes | $10 – $50 |
| UV / black light (365 nm) | Moderate–high — better fluorescence | Yes | $20 – $80 |
| CO2 lure traps | High — attracts bugs to inspectable surface | Yes | $30 – $150 |
| Interceptor / climb-up cups | High passive monitoring | Yes | $20 – $60 (set of 4) |
| Canine (dog) scent detection | Very high — professional grade | No | $200 – $500 per inspection |
| Thermal imaging | High — finds hidden bugs | No | $500+ (professional service) |
| UV-C sanitising device (Lumivyx etc.) | Very low as detection tool | N/A | Not a detection method |
What UV Light Cannot Do — Limitations
Being clear about what UV light cannot do is as important as understanding what it can reveal. Over-reliance on UV light for bed bug detection can lead to false confidence and delayed action in the face of a real infestation.
Key Limitations of UV Light for Bed Bug Detection
- UV light cannot confirm the presence of bed bugs — only physical observation of a live bug, dead bug, egg, or cast skin provides confirmation.
- UV light cannot penetrate surfaces — bugs hiding inside mattresses, walls, or furniture interiors are completely invisible to UV.
- UV light produces many false positives — laundry detergent, pet urine, lotion, and dozens of other common household substances fluoresce far more brightly than bed bug traces.
- UV light does not attract or drive away bed bugs — it does not help you see bugs in real time because they are already hiding in darkness.
- UV-C devices (sanitisers) do not serve as detection tools — they operate on a different principle entirely.
- UV light cannot kill bed bugs effectively — a brief flash of consumer-grade UV light is not lethal. Only sustained high-intensity UV-C at a very close range can harm them, and this cannot penetrate their hiding spots.
- A negative UV inspection does not mean no bed bugs — UV is not sensitive enough to rule out an infestation.
⚠️ If you suspect a bed bug infestation, a UV inspection is a useful first step — but a thorough physical inspection should always follow it and, if in doubt, a professional pest inspection. Do not rely on a negative UV result as confirmation that a space is bed bug-free.
Professional Bed Bug Detection Methods
When a thorough DIY inspection does not produce a clear result, or when you have confirmed evidence of bed bugs and need to understand the scope of an infestation, professional detection methods offer significantly higher sensitivity.
Pest Management Professional (PMP) Visual Inspection
A trained pest management professional uses a combination of bright light, magnification, and systematic inspection techniques developed through extensive field experience. Professionals know exactly where bed bugs concentrate — the top and bottom seams of mattresses, the internal wooden slats of box springs, the hollow sections of bed frames, behind outlet covers, inside picture frame backs, and along baseboards — and can identify even early-stage infestations that an untrained inspector would miss.
Canine (K9) Bed Bug Detection
Trained bed bug detection dogs are one of the most effective tools available for confirming bed bug presence. Dogs trained specifically for bed bug scent detection can identify infestations behind walls, inside furniture, and in locations completely inaccessible to visual inspection. Canine detection studies have reported accuracy rates of 95%+ under controlled conditions, though real-world accuracy varies based on the quality of the training programme and the handler.
- Typical cost: $200 – $500 per residential inspection
- Duration: 15–30 minutes for a standard home
- Best used for: Confirming presence after a suspicious visual inspection, or ruling out infestation before purchase of used furniture or real estate
When to Call a Professional
- You have found one or more live bed bugs anywhere in your home.
- You wake with unexplained bites in a linear or clustered pattern.
- You have found dark faecal spotting on mattress seams or upholstery.
- You have found shed skins or eggs in bedding or furniture joints.
- You have treated the infestation with over-the-counter products, but it has not resolved.
- You are purchasing used furniture, a used mattress, or a previously occupied property.
FAQs: UV Light and Bed Bugs
Q: Do bed bugs show up in black light?
Partially. Bed bugs themselves do not glow dramatically under black light, but traces they leave — dried excrement, shed skins, and egg casings — can exhibit a faint fluorescence. This fluorescence is subtle and inconsistent, and many common household substances (laundry detergent, pet urine, lotion) fluoresce far more brightly, making interpretation difficult. UV light is a useful supplementary inspection tool, but not a reliable standalone detection method.
Q: What colour are bed bugs under UV light?
Under UV or black light, bed bugs may appear with a faint pale blue-white sheen due to the fluorescence of chitin in their exoskeleton. This is subtle — not a dramatic glow. Recently fed bugs (darker in colour) show even less fluorescence. Shed skins appear slightly more luminous due to their translucency. The contrast is best visible in a fully darkened room.
Q: Does a black light show bed bugs?
It can make bed bug traces slightly more visible, but it will not make live bugs dramatically visible, as marketing images sometimes suggest. A bright white LED flashlight used during a systematic physical inspection of mattress seams, bed frame joints, and nearby furniture is a more reliable tool for actually seeing live bed bugs, eggs, and cast skins.
Q: Are bed bugs attracted to UV light?
No. Bed bugs are not attracted to any type of light, including UV. Their primary attractants are carbon dioxide, body heat, and chemical signals from warm-blooded hosts. Bed bugs are actually photophobic — they prefer darkness and will retreat from light rather than being drawn toward it.
Q: Are bed bugs scared of light?
Yes — bed bugs are photophobic and strongly prefer darkness. They feed at night and retreat into dark crevices during daylight. However, keeping lights on does not prevent bed bug feeding — a hungry bed bug will feed even in lighted conditions, especially late at night when a host has been still for an extended period.
Q: What is the best light to find bed bugs?
A bright, high-powered white LED flashlight is the most effective light for physically spotting live bed bugs, shed skins, and eggs. A 365 nm UVA black light, used alongside white light — as a supplementary tool — can help identify areas of organic residue concentration for closer inspection. The combination of both, in a darkened room, gives the best results for a DIY inspection.
Q: Does the Lumivyx HaloClean UV work for bed bugs?
Not as a detection or treatment tool for bed bugs. The Lumivyx HaloClean is a UV-C germicidal sanitiser designed to reduce surface bacteria and viruses. While UV-C light can technically harm insects at very close range with sustained exposure, it cannot penetrate mattress interiors, wall voids, or furniture joints where bed bugs actually live. It has no detection capability and is not recognised by pest control authorities as an effective bed bug treatment.
Q: What does UV light reveal about bed bugs that normal light does not?
UV light can make shed skins and areas of concentrated organic residue (dried excrement, skin oils) slightly more visible against dark surfaces. It can sometimes highlight clustering patterns of activity that are less obvious under white light. However, it does not make live bugs significantly more visible — white light does a better job of that.
Q: Can I use a black light to check a hotel room for bed bugs?
A black light can be part of a hotel room inspection routine. Focus the UV light on mattress seams, the headboard, and upholstered furniture. However, be aware that laundry detergent residues on bedding will glow very brightly and are not evidence of bed bugs. Look specifically for dark spotting (faecal marks) or clustered debris in seams and folds, then confirm any suspicious areas with a bright white flashlight and close physical inspection.
Q: Why does everything seem to glow under a black light?
Many common household materials contain compounds that fluoresce under UV light, including optical brightening agents in white fabrics and paper, laundry detergent residues, pet urine, some adhesives, and various cosmetic products. This widespread fluorescence is why UV light produces many false positives for bed bug detection — the vast majority of glowing spots have nothing to do with bed bugs.
Disclaimer
The information provided in this guide is intended for general educational and informational purposes only. Bed bug detection and treatment involves health, safety, and pest management considerations that vary by location, infestation severity, and individual circumstances.
Pest Identification: Information on bed bug detection methods, UV light behaviour, and the effectiveness of detection tools is based on publicly available scientific literature and pest management research. DIY detection methods, including UV light inspection, cannot substitute for a professional pest inspection. A confirmed bed bug infestation should always be assessed and treated by a licensed pest management professional.
UV Device Safety: UV-C devices emit radiation that is hazardous to human eyes and skin. Never operate UV-C devices without appropriate protective equipment and always follow the manufacturer’s safety instructions precisely. UVA black lights used at consumer intensities are generally safe for brief use, provided normal precautions are taken.
Product References: References to specific products, brands, and devices in this guide are for informational purposes only and do not constitute an endorsement. Product specifications, effectiveness claims, and availability change over time. Always verify claims with current manufacturer documentation and independent reviews.
Health Concerns: If you believe you have bed bugs, consult a licensed pest management professional. Bed bug bites can cause physical and psychological distress, and infestations can spread rapidly if not treated effectively. Do not delay professional treatment based on a negative UV light inspection result.
No Professional Advice: This guide does not constitute professional pest management, medical, or legal advice. The authors and publishers accept no responsibility for any outcomes arising from the use of information in this guide.
For confirmed or suspected bed bug infestations, always consult a licensed pest management professional for advice specific to your situation.