Do Bed Bugs Know When You’re Asleep or Awake?

Bed bugs are sneaky parasitic creatures that aren’t often seen during the day. Instead, they come out at night, while we’re asleep. This gives them the chance to feed without interruption. When it’s light, they hide away in harborages around the bedroom.

Bed bugs just know that night time (when it’s dark) is when humans are most likely to be inactive. Bed bugs can smell the carbon dioxide that we give off while we’re in bed, so that’s when they emerge to feed. The light will deter bed bugs from coming out, but not for very long.

We’ll look at why bed bugs come out at night, and whether it’s true that they only bite humans while we’re asleep. We’ll discuss whether you can deter bed bugs by sleeping with the light on. Finally, we’ll share some tips for sleeping with bed bugs, and ways of repelling them.

Why Do Bed Bugs Come Out at Night?

If you have bed bugs, you’ll know that they usually come out at night. They make themselves comfortable in mattresses, headboards and box springs, and rest during the day.

Bed bugs have to drink human blood, to survive. So, when your head hits the pillow at night, they come out to feast. In the morning (or several days later, depending on how your body reacts) you wake up with itchy bite marks.

So, why do bed bugs avoid light, and come out at night? Bed bugs are different from other parasites. Unlike fleas, ticks, and lice, they can’t live on our bodies full-time.

Their legs aren’t designed for clinging onto skin or hair. As we walk around, bed bugs get dislodged and end up falling off. The most they can manage it to climb on, feed, and then leave again.

This is why they choose to feed while we’re asleep. Every night, we lie down in bed and remain still for around eight hours. Bed bugs smell the carbon dioxide that we exhale, and come out to feed. We sometimes squash them when we roll over in our sleep, but the risk is minimal for them.

Bed bugs have learned to associate light with humans being awake and moving around. So, they wait until darkness falls before coming out of hiding.

Do Bed Bugs Only Bite When You Are Sleeping?

One of the common misconceptions about bed bugs is that they’ll only bite when you’re asleep.

It’s easy to tell where this myth came from. As we know, bed bugs prefer to avoid light, and of course, they chiefly live in beds. We don’t tend to spend much time in our beds unless we’re asleep. However, that does not mean that bed bugs only bite you when you’re sleeping.

Bed bugs can’t tell when a human is awake or asleep. As long as you are staying relatively still, you’re fair game to a bed bug. You can be bitten when you’re relaxing on the couch, for example.

If you have a home office, this is another prime bed bug spot. Bed bugs can live inside office chairs and electronics. There was even a case of bed bugs living inside a woman’s mouse mat. They bit her hand every time she used the computer.

So, while bed bugs do prefer to feed on a sleeping host, any period of inactivity will do. As long as you remain still long enough for a bed bug to feed.

Do Bed Bugs Come Out in the Light?

Bed bugs don’t like the light very much. This is obvious. Even in a heavily infested home, you probably won’t see many bed bugs moving around during the day.

Because of this, you may be wondering: are bed bugs light sensitive? Does the light hurt bed bugs in any way?

Unfortunately, no, it does not. Bed bugs may have an aversion to light, but it’s not because light harms them.

It’s merely because bed bugs are naturally nocturnal. The presence of light indicates that it’s the day time, which is when they rest.

Why are bed bugs nocturnal? Because humans aren’t. When we’re sleeping, we’re the perfect target. We generally don’t move much during the night. So, there’s less chance we’ll (accidentally or deliberately) jostle the bed bug while it’s feeding.

Electric lights fool bed bugs into thinking that it’s day time. They’re less likely to come out when we have a light on.

You can test this for yourself. Lie down in bed with the lights off, and wait for an hour. Then, switch the lights on. Chances are, you’ll see at least a few bed bugs scurrying away to hide.

Can Sleeping With the Lights On Deter Bed Bugs?

If bed bugs have an aversion to light, does that mean they’ll stay away if you sleep with the light on?

Unfortunately, if you want to deter bed bugs sleeping with lights on won’t help much. By all means, you can try it. Just don’t expect it to work for more than a couple of days.

bed bugs sleeping with lights on

Why doesn’t it work? Well, sleeping with the lights on will fool bed bugs (at first) into thinking it’s daytime. They’ll stay hidden until the lights go out. However, it can’t fool them for very long.

Sooner or later they’re going to get very hungry. Bed bugs can survive for months without a meal, but they don’t like to. They prefer to feed at least once a week if possible.

If they detect that you’re nearby, they’ll eventually come out and feed whether the lights are on or not. It’s as simple as that.

Tips for Sleeping with Bed Bugs

It can be challenging to get a good night’s sleep if your home is infested with bed bugs.

Falling asleep knowing that you’re moments away from having your blood sucked by insects isn’t easy. It causes very real anxiety and paranoia in most people.

So, here are some tips to help you sleep, knowing that your bed is playing host to parasites:

  • Relax in the evenings. Take a long, warm bath and read an old favorite book, for example.
  • Drink chamomile tea about an hour before bed. Not only does it help you fall asleep, but it also helps improve sleep quality.
  • Fall asleep while listening to soothing instrumental music, an audiobook, or a podcast. This will help to distract and ease your mind.
  • Take natural sleep aids, such as melatonin. If you are experiencing severe sleep deprivation, talk to your doctor about prescription sleeping pills.

You may be tempted to sleep in a different room – on the couch, for instance. However, it’s not a good solution. Changing where you sleep may distract the bugs for a few days, but they will eventually find you again. Bed bugs can smell the carbon dioxide that your body emits.

Likewise, you may also consider covering as much of your body as possible in bed, to give the bed bugs less access to skin. However, if you do this, the bed bugs will bite an area which isn’t covered by your pajamas – such as your face.

Can You Stop Bed Bugs From Biting at Night?

Unfortunately, if your home is infested with bed bugs, there’s almost nothing you can do to stop them biting.

Bed bugs need to drink human blood to survive, and they have a powerful will to live. If they can physically reach you, they will find you, and they will feed.

If you can’t get rid of the infestation completely, you can try to bed-bug-proof your bed. There are three main steps:

  1. Install a mattress encasement. These are like huge, zip-up bags that you place your mattress inside. They are designed to have no gaps, so that bed bugs cannot escape. Existing bed bugs get sealed inside, and can’t get to you. Eventually, they starve to death.
  2. Move your bed away from the wall and the window. This way, new bed bugs won’t be able to climb the walls or curtains to reach your bed.
  3. Install bed bug interceptor traps under the legs of your bed. These are designed to trap bed bugs when they try to climb up your bed legs.

If you follow the above steps, your bed should be safe. Unfortunately, they may still bite you in other areas of the home.

What Else Do Bed Bugs Dislike?

So, to summarize what we’ve learned, bed bugs don’t like the light. They prefer to come out when it’s dark, as there’s a better chance that we’ll be asleep.

However, switching on the light at night won’t deter bed bugs for very long. And while you can protect your bed if you’re through, the bugs will still exist in other parts of the home.

So, is there anything else that will repel bed bugs?

Extreme Temperatures

Bed bugs have adapted to live at the same temperatures as humans. They’re most comfortable at typical room temperatures of between 65 and 85 degrees Fahrenheit.

Both extreme cold and extreme heat can be fatal to bed bugs. However, they can survive easier in cold temperatures than hot ones. Unless the temperature is lower than 0 degrees Fahrenheit for at least four days, some bed bugs will survive.

Creating a sub-zero environment in your own home is hard. However, you can use heat to your advantage. Hand-held steam cleaners can deliver fatal blasts of scalding steam to beds, couches, and carpets. You can also launder your bedsheets at 140 degrees Fahrenheit to kill all bugs and eggs.


Insecticides, like pyrethroids, are somewhat effective at deterring bed bugs. They are poisonous to insects, so they will kill bed bugs upon contact. Most insecticides are sold in liquid form. You can brush them on, or spray them around the home.

The only trouble is that in recent years, some strains of bed bugs have developed a resistance to insecticides. There’s no guarantee that they will work for the specific bugs in your home. If you’d like to give pesticides a go, try buying a small bottle first to test it out.

Essential Oils, Alcohol, and Vinegar

There is some evidence that bed bugs are repelled by vinegar, alcohol, and essential oils. It’s likely that you’ll have some of these around the home anyway, so they’re worth a try.

Tea tree oil is effective against bed bugs, compared to other essential oils. It has a strong smell which bed bugs don’t like. If it actually touches a bed bug, it’s fatal. It’s not effective if diluted, though. Undiluted tea tree oil can also be harmful to humans and pets.

High-strength cleaning vinegar also repels bed bugs, and kills them on contact. It’s irritating to the skin, so wear gloves when using it. Unfortunately, it has a strong, unpleasant smell that lingers.

If you choose to use alcohol, you’ll need to opt for rubbing alcohol rather than drinking alcohol. It’s only about 50% effective at killing bugs, but it does repel them reasonably well.

Diatomaceous Earth

Diatomaceous earth is a sedimentary rock, sold as a white, talc-like powder. You can buy food-grade diatomaceous earth, which is safe to use around pets and children.

It’s a desiccant, which is the technical term for a drying agent. The small, sharp particles make tiny cuts in the waxy coating on a bed bug’s shell. The moisture inside evaporates, and is absorbed by the diatomaceous earth. Eventually, the bed bug dehydrates and dies.

Bed bugs can’t become resistant to diatomaceous earth. They will avoid it at all costs. Apply it to any area of the home that you think may harbor bed bugs.

Light Colors

Though it may sound strange, bed bugs have a preference for certain colors.

According to a study in the Journal of Medical Entomology, bed bugs actively avoid harborages (hiding places) that are yellow or green. They prefer darker colors, such as red, black and purple.

Unfortunately, buying yellow bedsheets isn’t enough to get rid of a bed bug infestation. It will, at best, put them off for a few days. If a bed bug is at risk of starving, they’ll find you and feed.

Similar Posts:

Photo of author

Lou Carter

Hi, I'm Lou. I’ve long been fascinated by bed bugs, ever since a friend’s life was turned upside down. That’s why I’ve put together this specialist site. You’ll find detailed answers to all of your questions on how to get rid of a bed bug infestation. I hope you find it useful!

1 thought on “Do Bed Bugs Know When You’re Asleep or Awake?”

  1. So, I’m thinking the fact that I found one crawling on me, coupled with the fact that I’ve had diatomaceous earth around for almost a month, that it was trying to find a place to bite out of desperation. The light was on, I was moving so I was very much awake, but it was still bold enough to try and get me in an attempt to say alive.

    I’ve also been seeing less bites less often so that’s gotta mean that it’s working. And because I’ve been toughing it out by sleeping only in my room, no one else in the house seems to be getting bit.


Leave a Comment