Why do bed bugs come out at night? Plus how to get them out of your mattress

Bed bugs scrambling about on a mattress
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If your mattress has ever been infested with bed bugs, you've probably noticed that these critters only seem to be active at night-time. But what are bed bugs, and why do they come out at night?

We've tested a wide range of top-quality beds for our official best mattress guide, and we're sorry to report that no mattress is ever truly resistant to bed bugs. These crafty bugs also come out at certain times, usually when we're asleep, so it can be hard to stop them in their tracks.

Here, we'll take a look at what bed bugs are and why they come out at night. Bed bugs can also wreak havoc in your home, so we'll share some advice on how to rid them from your mattress, too. 

What are bed bugs?

A bed bug up close

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Bed bugs are parasitic insects that suck the blood of humans and animals. They have reddish brown oval-shaped bodies and are tiny (about 5mm in length), so they’re difficult to spot. They tend to dwell in dark, concealed places that are near to their host, which is why they can be found in mattresses and furniture. 

Female bed bugs can lay up to 250 eggs a lifetime so it's easy for a mattress to become infested. While bed bugs don't transmit disease, they are a health concern so it's important to act fast when you spot the signs of bed hugs in your home.

Where do bed bugs come from?

A black suitcase in front of a white bed in a stylish hotel room

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There are many places where you probably never realized you could pick up bed bugs. By knowing how bed bugs can enter your home, you can try to prevent an infestation. They usually spread through used furniture, such as second-hand furniture in antique stores or flea markets. 

Hotels are the most common places bed bugs hide due to their mattresses being used by so many different guests or if the hotel has a subpar cleaning service. If you're traveling, we have some advice on how to spot bed bugs in hotel mattresses. They can also spread through unworn clothes, so bed bugs can be found in suitcases, laundromats, and coat checks. Due to bed bugs liking the regular turnover of people, you'll also find bed bugs in popular places such as public transport, restaurants, and cinemas.

Why do bed bugs come out at night? 

Bed bugs in the bottom of a wooden drawer

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First of all, bed bugs prefer darkness as they're highly sensitive to light. In fact, sunlight (or any UV light) can kill them. This is why they tend to dwell in dark crevices during the day. 

Secondly, bed bugs tend to come out at night as this is when their host (i.e. us) is usually fast asleep. They like to feed on our blood when we're asleep as they're attracted to carbon dioxide, which we exhale while sleeping. 

We also tend to stay still while sleeping, so its easier for bed bugs to feed on our blood without being crushed by our movements. Bed bugs also love warmth, particularly body heat, so the bed bugs' nocturnal feeding habits are exacerbated by warm, cosy bedding and a mattress that retains your body heat. 

How to get rid of bed bugs

First things first, it's important you seek professional help if your home is infested with bed bugs. However, there are many DIY methods for tackling a bed bug infestation than can be combined with professional pest control. We also reccomend checking out our extensive guide on how to get rid of bed bugs

How to get rid of bed bugs by vacuuming

Woman wearing beige shorts vacuuming her white mattress to get rid of bed bugs

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When vacuuming your mattress, pay special attention to the corners and crevices to remove bed bugs, eggs and any debris. Once you're done, take the vacuum outdoors and empty and clean it outside of your home. If you do this indoors, you risk opening up the rest of your home to infestation. 

How to get rid of bed bugs by steam cleaning

Person steam cleaning a white mattress to get rid of bed bug residue

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While bed bugs like warmth, they do not enjoy extreme heat, so steam can be an effective method for killing bed bugs. However, the steam needs to be at least 130°F to kill bed bugs, their eggs, and larvae. Also, you don’t want the air flow to be too powerful or it can blow bed bugs away. 

Always check the mattress's label for care instructions, as some mattresses (particularly memory foam ones) cannot be cleaned this way. For further info, read our guide on how to steam clean a mattress to get rid of bed bugs. 

Frances Daniels
Sleep Staff Writer

Frances Daniels is a Sleep Staff Writer at Tom's Guide and her role includes covering all mattress and sleep news, in addition to mattress reviews and buyer's guides, plus sleep accessories such as pillows and mattress toppers. Frances is a PPA-accredited journalist and is hugely interested in the relationship between good sleep and overall health. When not writing about mattresses and sleep for Tom's Guide, Frances enjoys writing about women's issues, health and wellbeing, the environment, and her native Wales.