Bed bugs hide to survive: If you can’t find them, you can’t kill them. They crawl into tiny cracks and dark places, and only come out when they have to – or when you use the tactics in this post to draw them out.
There’s no sure-fire way to lure all bed bugs out, but using a combination of methods over a few days or weeks will help you find, trap, and/or kill bed bugs. If you do find bed bugs, you have confirmation they’re around and you can take steps to get rid of them.
In this post, you’ll discover
- 2 reasons why bed bugs come out, which you can use to your advantage
- 8 things you can try to get bed bugs out in the open
Why bed bugs come out of hiding
Bed bugs come out of hiding for two reasons:
- They’re hungry
Most bed bugs get hungry about once a week. When they’re hungry and they know someone is close enough to crawl to and bite, the bed bugs come out of their hiding places to feed on that person’s blood.
Bed bugs know when there’s someone sleeping in a bed or sitting on a couch nearby because they can sense that person’s body heat and smell the carbon dioxide the person breathes out.
- They breed quickly and need to spread out
Bed bugs breed very quickly, which means their numbers multiply within a few short weeks and keep growing.
Most bed bugs first hide in a mattress or box spring for convenience, because it’s close to where people sleep and makes feeding on people easy.
But a box spring or mattress can only hold so many bed bugs. As more bed bugs hatch from eggs and mature within days, depending on the temperature, it becomes necessary for younger bed bugs to start moving out from the bed to other objects close by.
Here’s an article where I explain how bed bugs spread and where they hide through a house as their numbers increase.
How to draw bed bugs out of hiding
Bed bugs are drawn out of hiding when they think there’s someone close by to bite. You can trick them by imitating a person’s body heat and releasing carbon dioxide into the air. Bed bugs also come out when their hiding places are made uncomfortable with things like high heat or insecticide.
There are many things you can use to lure out bed bugs. To draw bed bugs out of hiding, try a combination of the following:
Put clutter and dirty clothes on the floor
Bed bugs like to hide in warm, dark places such as soft toys, shoes, and dirty clothes that smell like humans. To draw bed bugs out of hiding, put items like these close to the bed or even on the bed, and leave them there for at least a week.
Bed bugs choose dark colors when they have a choice, and their favorite colors are black and red. If you’re leaving out items for bed bugs to hide in, leave out red and black clothes that you’ve worn or sheets that you’ve slept on. [source]
Every few days or so, carefully inspect the clutter to see if there are bugs or signs of bed bugs in there. Catching a live bed bug will tell you for sure that you have bed bugs. Here are all the other signs to look for to tell if you have bed bugs.
If you find bugs, trap one on clear tape or trap some in a sealable plastic bag. Show these bugs to your landlord or a pest control expert to get confirmation that you have bed bugs. If you want to identify them yourself, use this detailed guide from the University of Minnesota.
Take steps to kill all the bed bugs in the clutter trap you set. I suggest using heat, which you can do by washing and drying the items for at least 30 minutes on high heat. Click here for a list of all the ways to kill bed bugs, so you can choose a method that works for you.
Keep the room dark until 4 a.m.
Bed bugs prefer to come out of hiding when a room is dark, usually at around 4 a.m. This is when people are sleeping and probably won’t see bed bugs crawling over them.
However, if a person works night shifts and only sleeps during the day, bed bugs adjust their schedule to come out during the day to feed because they have to.
If you’re trying to lure bed bugs out of hiding, make the room dark at night if this is when you normally sleep. If you sleep and get bitten during the day, make the room as dark as you usually have it when you’re sleeping.
Leave the room dark for several hours before suddenly turning on the light. For the best chance of catching bed bugs, do this at 4 a.m.
Now quickly check the mattress, box spring, linen, couch, or around any items near to where you get bitten.
If you do see bed bugs, kill them with one of these methods, or catch some in a glass jar or on clear tape, for easy identification.
Use heat to make bed bugs think a host is nearby
One way bed bugs find a host in the dark is by sensing the body heat that a person releases. Once bed bugs sense body heat, they become active and start crawling to the source of the warmth to feed.
If you’re trying to get bed bugs to come out of hiding, you can use heat to make them think there’s a host so they come out.
The best way to draw out bed bugs is to use a heat source that’s only slightly warmer than room temperature, much like your body is.
In fact, it’s a good idea to take your own temperature in the room to see what temperature a bed bug expects to sense on a host, then make the heat source the same as your own body temperature or a temperature that would be comfortable near your body.
For example, you wouldn’t be able to sit next to a strong electric heater for a long time, so a heater is probably too hot. Bed bugs stay away from high heat, like heaters, because a mere 10 seconds of very high heat can kill them.
Heat sources you could try include a heated blanket, electric socks, or even a food warming tray on low as a heat source to lure bed bugs out.
Bed bugs have a few ways to sense that a host is nearby, and heat is only one of them. They might be able to sense heat from a distance, but they still have to find where it’s coming from.
If a bed bug uses only heat to find a person to bite, it needs to be within an inch (3 cm) from that person. This is why bed bugs use many senses and techniques to find food in a room. [source]
So heat cannot be used on its own to draw out bed bugs. Heat needs to be combined with other methods in this list for the best results.
Make it so hot that bed bugs have to come out
If you know where bed bugs are hiding, you can use high heat to make them uncomfortable and force them out of hiding.
10 seconds of direct high heat kills bed bugs. But if you can raise the temperature in their nesting area to 77°F (25°C) or higher, the bugs should quickly come out of hiding.
Try running a steam cleaner or clothes steamer over the mattress, box spring, and other places where bed bugs are taking cover. You can also point a hairdryer on high heat at any bed bug nesting areas.
Release carbon dioxide so bed bugs think food is near
People breathe out carbon dioxide, so bed bugs have developed ways to sense when there’s carbon dioxide in a room and find where it’s coming from.
To get bed bugs out of hiding, try activating a carbon dioxide bag in the room.
You can also build a dry ice trap. Click here for full instructions on how to do this on the Rutgers University website. Dry ice releases carbon dioxide as it turns to gas when it isn’t kept cold.
The bed bugs will sense the carbon dioxide, and if they’re hungry, they are likely to come out of their nesting areas to feed.
If you’re interested to see how bed bugs wake up and become active when they smell carbon dioxide, watch the following video of a man who caught bed bugs in a polystyrene cup and breathed on them…
Use yourself as bait to bring out bed bugs
As uncomfortable as it is to think about letting bed bugs come to you, you are the best way to lure bed bugs out of hiding. Especially if you’re the person the bed bugs usually bite (click here to find out why bed bugs bite some people and not others).
Bed bugs feed on people and are most drawn to real humans. Lying down in an infested room releasing your usual body heat, carbon dioxide, and human smells is the best way to get bed bugs to come out.
In fact, if you had to use several methods in this blog post all at once and lie in the room at the same time, bed bugs would come out and crawl to you before being tricked by any of the other methods.
Scrape bed bugs out of hiding
Bed bugs love hiding in small places that are difficult to reach.
They might start off at the back of the bed by a wall, where it’s dark.
But if left alone to breed and increase in number, they soon move into cracks in nearby furniture, gaps between floorboards, behind base boards, and into walls.
If you know bed bugs are hiding in a hard-to-reach place, scrape them out with something that’s hard but flexible, and strong enough to slip into the gap and disturb sleeping bed bugs. You could try using a playing card or a paint scraper (putty knife) to do this.
Set a bed bug trap
There are two options when it comes to setting a bed bug trap:
- Buy a trap
Bed bug traps are available to draw out bed bugs, like this one.
Most traps release odors that smell like humans, so bed bugs are attracted to the trap. Once inside, the bed bugs can’t get out, and you can see what the traps caught in the morning.
- Make a bed bug trap with bait
The best bait for bed bugs was created by Rutgers University and contains 26 oz (750 g) of sugar mixed with 5 oz (150 g) of active dry yeast in 3 qts (3 l) warm water.
The video below shows you how to make this yeast and sugar bed bug bait and trap.
When these ingredients are combined, they react and let off carbon dioxide. Bed bugs sense the carbon dioxide in the air and think it’s a person, so they come out of hiding to feed.