Bed bugs are sneaky little creatures that can hide in the smallest of cracks and crevices. Even though you may not see them, they can still be present and biting you at night. So what draws these pests out of their hiding spots and gets them crawling onto your bed?
Bed Bugs Are Attracted to Carbon Dioxide and Body Heat
Bed bugs are attracted to the carbon dioxide we exhale with each breath. They can sense CO2 from over 100 feet away! This allows them to hone in on a human host to get their next blood meal. Along with carbon dioxide, bed bugs use thermal cues to find a warm-blooded victim. They are drawn to the body heat we emit, which is why they often congregate around the warmest parts of the body, like the face, neck, and arms.
Movement and Vibrations Bring Bed Bugs Out
Once bed bugs are in your general vicinity, sudden movements and vibrations will cause them to mobilize. The shifting of a mattress, leaning over the bed, or even rolling over at night can rouse bed bugs from their hiding spots. They emerge to investigate potential hosts that may lead them to a blood meal. That’s why merely sitting on a bed for an extended period can prompt bed bugs to start crawling on you, even during the daytime.
Dim Lighting Triggers Bed Bug Activity
Bed bugs are naturally more active at night. They prefer darkness and are sensitive to bright light. That’s why these vampiric insects emerge after dusk when the lighting becomes dimmer. Artificial lighting at night also stimulates them, but to a lesser degree. During the day, bed bugs will remain firmly hidden in cracks and crevices to avoid detection.
Bed Bug Feeding Habits
Bed bugs typically feed every 5-10 days. After this duration without a blood meal, they will emerge from hiding to seek out a host. Their flattened bodies allow them to reside in tiny spaces for long periods between feedings. However, when the bugs become metabolically starved, they will risk exposure to find a meal. Clustering around beds maximizes their feeding opportunities when a sleeping human presents itself.
Certain Chemicals and Scents
Bed bugs seem to have a strong affinity for certain chemical odors that signal a nearby host. Studies have shown that compounds emitted from used mattresses, dirty laundry, and even human skin attract and stimulate bed bugs. Pheromones secreted among groups of bed bugs help aggregate them around favorable feeding locations. Specific pheromones have been identified that signal a bed bug’s readiness to feed and prompt others to want to feed as well.
Increased Bed Bug Activity in Spring and Summer
Bed bug infestations tend to worsen in the warmer months. During spring and summer, bed bugs reproduce at a faster rate and become more active. The warmer temperatures speed up their metabolism, causing them to feed more frequently. Higher ambient temperatures also allow them to spread farther throughout a home or apartment building. This upsurge in activity makes bed bug problems more evident during the summer.
Disruption of Their Harborage Areas
Under normal circumstances, bed bugs prefer to stay hidden safely in their secluded harborage areas. However, when their hiding spots become compromised, such as from vacuuming, moving furniture, or application of pesticides, they will evacuate in search of new shelters. The bugs may temporarily end up in unusual visible locations as they scramble to find new cracks and crevices to inhabit.
Strategies to Draw Out Bed Bugs
While bed bugs prefer to stay concealed, you can purposely lure them out of their comfort zone to help detect an infestation. Some effective strategies include:
- Using carbon dioxide traps – Dry ice releases CO2 which mimics human breath and attracts bed bugs.
- Applying heat to areas – A hair dryer or heater probe draws bed bugs towards the warmth.
- Using a clutter-free bed – Bed bugs have fewer spots to hide on a bare mattress encased in a protective cover.
- Installing passive monitors – Traps and interceptors catch bed bugs as they traverse around a bed.
- Using a CO2-generating yeast/sugar mixture – This artificial host scent pulls bed bugs from their harborage.
These proactive measures can confirm if bed bugs are present so you can take appropriate control measures.
Signs of Bed Bugs Even When Not Seen
Sometimes even if you don’t see any bed bugs, their presence can still be confirmed through other evidence they leave behind:
- Bites – Finding itchy welts on your body in the morning is a telltale sign of bed bugs.
- Blood spots – The bugs leave behind small dark blood stains from crushed bugs or their excrement.
- Eggs – You may find pearly white eggs in cracks and crevices near sleeping areas.
- Exoskeletons – The molted outer shells of bed bug nymphs can confirm an infestation.
- Odor – Some describe the smell of a bed bug infestation as sweet or musty.
So even without seeing actual live bed bugs, these remnants provide clues that the sneaky pests are still around and feeding on you.
Preventing Bed Bugs from Hiding in Belongings
When not feeding, bed bugs will hide in dark, undisturbed locations. Clothing, bedding, furniture, suitcases, and other belongings make perfect hiding spots when not in use. To deter bed bugs from infesting your personal items:
- Inspect and treat luggage after traveling before bringing it inside.
- Keep clothing and linens protected in sealed plastic containers or bags.
- Wash and heat dry clothes and fabrics at the hottest setting after exposure.
- Store unused items in sealed plastic totes to prevent bed bug access.
- Vacuum suitcases thoroughly after trips before storing away.
Why Bed Bugs Come Out When Lights are Off
Bed bugs typically only come out in the dark to feed. There are a few key reasons why bed bugs hide when the lights are on:
- They have an aversion to bright light and direct sunlight.
- Darkness provides cover from detection by hosts.
- Their extra sensitive antennae work better in darkness.
- Increased activity of hosts at night when sleeping.
- Darkness cues their biological clock to search for food.
So when the lights flip off and the room goes dark, that’s the signal for bed bugs to come out of hiding in search of an unsuspecting sleeper to bite for their next meal.
How Far Bed Bugs Travel from Their Harborage
Studies have shown bed bugs can travel a surprisingly long distance from their harborage to find a host. Some key facts on their mobility:
- Adults can travel over 100 feet to seek out a blood meal.
- Nymphs are limited to shorter distances closer to 20 feet.
- They can migrate between adjoining rooms in multi-room dwellings.
- All bed bugs can spread to neighboring living spaces in apartments.
- They will crawl up walls, under baseboards, through vents and wiring to reach new areas.
The small size and flat bodies of bed bugs allows them to fit through extremely narrow gaps to expand their range. Limiting clutter and sealing cracks can help restrict their movement throughout a home.
How Bed Bugs Know When You’re Asleep
Bed bugs are extremely strategic about when they come out to feed. They prefer to bite sleeping humans in the middle of the night when we are unaware and unlikely to notice them. Bed bugs know you’re asleep and safe to feed on through these innate sensing abilities:
- Detect when a person is motionless for an extended period.
- Sense carbon dioxide levels drop as breathing slows.
- React to lower body temperature of the host.
- Associate lack of noise and vibrations with sleeping.
- Are sensitive to melatonin hormonal changes in the host.
Even in pitch dark conditions, their keen senses allow bed bugs to determine the optimal time to come out when the host is in a deep sleep. This ensures they can feed undisturbed for about 5-10 minutes, then slip away unseen back into their hiding spots.
Daytime Hiding Spots of Bed Bugs
During the day when they are not active, bed bugs need to hide in concealed, undisturbed spaces. Their flat, pliable bodies allow them to squeeze into the narrowest cracks. Typical daytime harborage sites include:
- Inside mattresses and box springs
- Behind headboards and bed frames
- Under loose wallpaper and paneling
- Inside furniture cushions and seams
- Under carpeting near baseboards
- Inside screw holes and electrical outlets
- Behind wall hangings and baseboard molding
- Inside clutter like piles of books, toys, shoes, etc.
Finding their hiding spots during inspections takes patience and a keen eye. Eliminating clutter forces bed bugs out into more exposed areas where they can be detected and removed.
Do Bed Bugs Come Out Every Night to Feed?
Bed bugs do not necessarily come out and feed every single night. Their feeding frequency depends on the size and life stage of the bug, availability of hosts, and environmental conditions. Here is a summary:
- Adults – Feed about every 5-10 days.
- Nymphs – Feed about every 3-5 days.
- Newly hatched nymphs – May feed daily for several days.
- Well fed bugs – Can go weeks between feedings.
- When hosts are scarce – Feed less often.
- Warmer temperatures – Increase feeding activity.
While they don’t need to feed nightly, most bed bugs will take any opportunity to bite and consume more blood meals when given the chance.
Table: Typical Nightly Feeding Patterns of Bed Bugs
The following table summarizes the usual feeding behavior of bed bugs at night under normal conditions:
|Timeframe||Bed Bug Activity|
|Early evening||Emerging from daytime hiding spots|
|After 9 pm||Attracted to sleeping areas by carbon dioxide, heat, pheromones|
|After midnight||Crawl onto exposed skin and begin feeding|
|Towards dawn||Return satiated to harborage to hide and digest meal|
This pattern may vary based on environmental conditions, host availability, and if control measures are being implemented.
Why It’s Hard to Find Bed Bugs During the Day
Bed bugs are masters at hiding during daylight hours. They disappear into tiny cracks, crevices, and voids that are extremely difficult for humans to see into. Here are some key reasons bed bugs are hard to find in the daytime:
- Their flat, thin profile allows them to squeeze into narrow spaces just 1-2mm wide.
- They wedge themselves into mostly inaccessible hidden spots.
- Their brown to red color provides camouflage against common backgrounds.
- Bed bugs often congregate together in large hard to detect groups.
- Their eggs are tiny and laid directly into cracks making them easy to overlook.
- They avoid light and retreat deeper into crevices when disturbed.
Taking apart beds, using flashlights to peer behind furniture, and utilizing detection tools can help reveal their clandestine hiding spots.
Bed bugs are highly strategic about when and where they congregate. Their natural tendencies to hide in concealed spaces and come out when we sleep make them very challenging to detect and eliminate. Understanding their secretive habits and being vigilant for signs of infestation are key to controlling these parasitic pests.