Written by A O’Neill, Licensed Pest Management Professional
Bed bugs are mainly nocturnal and hide away for most of their lives close to where you rest or sleep, only leaving their harborage areas at night to take a blood meal.
However, they will adapt to your sleeping patterns so they can feed and will come out during the daytime if they are especially hungry, or for example, you work at night and sleep or rest during the day.
They will also venture out when the lights are on at night if they need to feed, so keeping the lights on will not deter these parasites from biting you.
Why Do Bed Bugs Hide In The Daytime?
Bed bugs are photophobic which means they are sensitive to light, so they prefer to keep themselves hidden during daylight hours and only come out to feed when it’s dark.
After a feed, which can last for up to 10 minutes, they go back and congregate in their dark harborage areas which are usually within 8ft of where you sleep. But they are more likely to be within 3-6ft.
They will then stay hidden for between 5-10 days, and during this time they digest their blood meal, mate, and lay eggs.
Not a nice thought!
How To Find Bed Bugs During The Day
Although bed bugs like to hide close to a host, they can still be hard to find as they are so small and flat and they can fit inside the tiniest cracks and crevices to avoid detection.
Studies have found that 85% of bed bugs are found in or near the bed. So during the day, the obvious hiding places to focus on are:
- the mattress – lift the mattress and inspect the surfaces and look in the fabric creases, and inspect the seams
- bed frame – you might need to dismantle it and inspect the joints and screw heads
- headboard – bed bugs are often found hiding at the back of the headboard
- box spring – inspect the seams and surfaces
A flashlight and magnifying lens are handy tools to use when searching for these pests and will make finding them so much easier. When you’re searching for them in the daytime, make sure you have as much daylight as possible in the room, so fully open the curtains, blinds, etc.
If the infestation is in the early stages, then it can take time to find them, so you’re going to need to be patient and as thorough as possible.
When inspecting the above hiding spots, there are also characteristic signs to look for which indicate their presence if you can’t find an actual bug, and these include:
- dark spots and stains (which look like dried pen ink) that are actually dried fecal matter.
- reddish-brown smears on your bed sheets or mattress from crushing the bed bugs when you’re sleeping, and the crushed bed bugs themselves.
- Bed bug bites – you might wake up with some red welts on areas of skin that are exposed when sleeping, such as the face, arms, shoulders, etc. However, not everyone reacts to the bites.
After a feed, female adult bed bugs lay their eggs in dark, secluded areas where they won’t fall prey to other insects. The eggs can be extremely hard to find because they are only 1mm in length, so to give you some idea of their size that’s about the size of a pinhead or a grain of sand.
Bed bug eggs are white in color and are cemented onto surfaces, which include rough surfaces like wood. They can be even harder to detect on light-colored surfaces and fabrics, so slowly take your time when looking for them.
My article on how to get rid of bed bugs gives you step by step instructions on where to look and what to look for.
Baby bed bugs, or nymphs, also hide during the day just like the adults. They go through 5 molts, shedding their skin each time before becoming adults. These shed skins are tan-colored and will also be found in the same harborage areas but are easier to spot when it’s light during the daytime.
So, we know where the majority of the infestation is found, but where else could these pests be lurking?
Well, the remaining 15% of the infestation is usually found in upholstered furniture, bedside cabinets, curtains, along baseboards, and behind electrical plates, etc., as bed bugs prefer to hide on fabric and wooden surfaces.
Although these pests can initially be found in the above areas, once the bed bug infestation starts to grow they will spread out and hide in other parts of the room, making it more difficult to eradicate them. They will also be more visible during the day.
Why Am I Seeing Bed Bugs During The Day?
There are several reasons why you could be seeing bed bugs in the daytime.
One reason that I’ve previously mentioned, is if you work during the night and sleep or rest during the day. The bed bugs will adapt to your sleep pattern and take their blood meal in the day instead.
Bed bugs are incredibly resilient insects that have adapted to live with us to ensure their survival.
Another reason, as I said above is when the population of bed bugs increases over several months and the harborage areas become overcrowded, so the bed bugs have to move out and spread out to other areas of the room, making it much more likely that you will see them during the day.
As you know, bed bugs prefer to stay within 8 ft (2.4m) of where you sleep, but it has been reported that they will crawl more than 100 feet (30 meters) in a night to get a blood meal.
Did you know that an infestation can grow from a single pregnant female? And as long as there is access to a host for feeding, the infestation will continue to grow resulting in a heavily infested room/home.
But there is also another possible reason why you see bed bugs during the day, and that is because it might not actually be bed bugs, but an almost identical pest, which is a bat bug.
Believe it or not, before the recent resurgence of bed bugs, bat bugs were the more common species of Cimicidae to be found in homes.
Bat bugs (also called bat mites) feed on bat blood and only feed on people when bats are no longer available.
So if you’ve recently had bats removed from somewhere in your home, then it could possibly be bat bugs you are seeing.
These blood-sucking pests find their way through cracks and crevices from the attic and into our living areas for a meal.
The good news is that human blood cannot sustain bat bugs, so they will not be able to reproduce and will die out. Having said that, you still don’t want them in your home and feeding on you.
What does a bat bug bite look like? Bat bug bites and reactions to them are basically the same as bed bug bites and can cause skin irritation and itchy, red welts which makes them almost impossible to tell apart.
Thankfully, neither bed bugs nor bat bugs transmit any disease-causing pathogens.
But whatever the reason might be for seeing bed bugs during the day, it’s always advisable to get a licensed pest control company to come out and investigate further.
What Time Do Bed Bugs Come Out?
Studies suggest that bed bugs typically come out from their hiding places to feed between the hours of 1 am and 5 am. This is thought to be because the host is usually in a deep sleep between these times.
Although being in a deep sleep gives the bed bug a more successful chance of getting a full blood meal, there are other attractants that lure them out, such as the carbon dioxide (CO2) we exhale which is the primary attractant, followed by the warmth from our bodies and other chemical compounds we emit.
No one likes the thought of bed bugs feeding on them when asleep and crawling up on our mattress to get to us, but one way to capture them and monitor the population level is to install bed bug interceptors under each leg of the bed.
These interceptor traps work passively day and night and prevent any bed bugs from being able to climb up your bed and onto your mattress and feed.
Read here on how bed bug interceptors work and why they are a useful detection tool that helps confirm whether you have bed bugs or not.
Can You See Bed Bugs With The Naked Eye?
Yes, adult bed bugs can physically be seen with the naked eye. But they can be hard to find as they are small and excellent at hiding, so look in the harborage areas such as the ones listed above for a better chance of spotting them.
Do you know what these parasites look like? See these images of bed bugs so you know what to look for and their identifying features
However, nymphs, especially 1st stage baby bed bugs are particularly hard to spot because of their size and because they are nearly see-through. These nymphs, like the eggs, are especially difficult to see against a light-colored background.
But they can be slightly easier to spot if they have fed as the blood from a feed is visible inside their abdomen, as the picture below shows.
Pest control exterminators are trained to spot an infestation and we know where bed bugs hide, but even then they can still be hard to spot.
Although you can visually see bed bugs, they are easily and often mistaken for other pests so I advise to try and get them identified by a trained pest control technician or entomologist.
I’ve seen this mistake made many times where I’ve been called out to a home where they think they’ve seen fleas and it’s turned out to be bed bugs. Believe me, the last thing you want is bed bugs and for the infestation to grow.
Another thing to think about is how bed bugs got into your home in the first place. The most common way (but there are others) is through travel where they hitch-hike a ride back with you in your suitcase. Finding out how you got them is important to prevent future infestations.
As you can see, there are several reasons why bed bugs come out during the day but we know they don’t like the light and prefer to stay hidden so they can’t be found.
So, are you seeing them because the infestation is growing and the harborage areas are becoming overcrowded? Or, is it because you or another person in your household sleeps or rests during the day, or is it a different pest altogether?
Although bed bugs are not strictly nocturnal and are opportunists that will crawl out of hiding during the daytime to feed, the chances of actually seeing them are slim, so finding out why they are visible during the day is vital!