spider beetle

by nobugsonme on March 11, 2008 · 38 comments

in bed bugs, not a bed bug

Photo courtesy of Lou Sorkin. This spider beetle, a stored product pest, is commonly confused with a bed bug.

Click the photo, then “all sizes,” then “large” to see in more detail.

Thanks, Lou!

spider beetle

Originally uploaded by louento.pix

1 Rob May 16, 2009 at 4:21 am

I found three bugs that look just like these guys on my box spring and under my bed this evening. They didn’t look quite like bedbugs to me (very rounded instead of the flat images I’d seen for bedbugs). My question is, are spider beetles known to roost in beds?

2 nobugsonme May 17, 2009 at 1:16 am

Not particularly, Rob, but it is amazing what bugs you will find when looking for bed bugs. Lots of us have found spider beetles.

3 Julie May 18, 2009 at 9:00 pm

Hi, I’ve got the same thing. I just threw out my box spring thinking maybe that’s were they were staying. I’ve got a collection of welts on my left shoulder blade.
They burn and hurt, but no bite hole. How are you getting rid of them?

4 nobugsonme May 19, 2009 at 12:48 am

Hi Julie,

You may have spider beetles, but we are told they do NOT bite people.

You may or may not also have bed bugs which are causing your bites. If you think you may have bed bugs, here are some tips on getting a definitive answer, as well as some other possibilities for what might be causing the problem.

5 Kia May 24, 2009 at 7:31 pm

I def have these beetles how do I get rid of them and tips on keepin them from coming back

6 nobugsonme May 25, 2009 at 2:44 am


Spider beetles do not bite. Any pest control professional should be able to help you.

7 Joanna May 29, 2009 at 2:31 pm

I recently moved from a bed bug infested apartment where one of my roomates had brought them in from staying at a friend’s place and can not go thorugh another infestation! This afternon I found a bug crawling on my wall that looked exactly like the spider beetle image posted above and I was wondering if it was common for bed bugs to come out during the day or if it was actually a spider. In my last apartment I had found what looked exactly the spider beetle in the bathroom, but had assumed it was a bed bug. Thanks!

8 nobugsonme May 31, 2009 at 1:13 am

Hi Joanna! I fully understand your concerns about going through another infestation, having dealt with bed bugs.

However, if you have something and you’re sure it looks like a spider beetle, it probably is one. (You could probably walk into any pest control business with a sample and get this confirmed).

They do NOT bite and are not a big deal, though I understand they can be stored grain pests. Lots of us have spider beetles. And they’re not spiders, but a kind of beetle.

9 Brett July 1, 2009 at 12:45 pm

Having had a pretty terrible bed bug infestation before, about every 3 – 6 months i go through a fairly serious “bedbug scare” where after finding any sort of bug bite or itchy spots i take preventative measures by cleaning everything and putting down pesticides from the hardware store. Since then i haven’t had another infestation and don’t know if these efforts help that or not.

Anyways during the last two scares i found these beetles and am curious if they are at all similar to bed bugs in their resistance to pesticides?

10 nobugsonme July 1, 2009 at 8:59 pm

I don’t know enough about them, Brett. If you really want to know, feel free to copy your question to our forums: http://bedbugger.com/forum

Be assured that spider beetles are not a problem and don’t bite.

11 Gabb September 26, 2009 at 9:28 am

i see a spider beetle about once a week or so but i have bites and i havent seen a bed bug. i was told dat spider beetles dont bite but wat is it dat is biting me???

12 Hap September 29, 2009 at 7:10 am

We, too, have spider beetles. We’ve also had sporadic bites–they are very itchy, but are small and go away in 2-3 days. We had a bed bug problem 1 year ago, and while I’m pretty confident these are NOT bed bugs, I am wondering what they might be? Anyone have any thoughts?

13 mike c September 29, 2009 at 11:28 pm

i would like to know, why would spider beetles mainly be upstairs in an apartment and continue to be there after a pest treament.

14 nobugsonme September 30, 2009 at 12:34 am

Gabb and Hap,

Bed bugs hide easily. It’s rare to see one. So it is entirely possible you have bed bugs (or some other cause of your skin problem) and also happen to have spider beetles.

Please see a doctor to rule out scabies, folliculitis and other causes. I suggest you also have a knowledgeable and experienced pest pro rule out (or eliminate) fleas, mites, or bed bugs in your home.

In rare cases, we have heard people can be so sentitive to insects that they react allergically merely to the presence of an insect which does not bite.

However, so many people who are searching for bed bugs find spider beetles, and I suspect most of them do not fall into this category.

mike c.,

I do not know, sorry!

15 freya January 13, 2010 at 1:11 am

i just moved into a new apartment a little while ago and discovered these disgusting things in all the lighting fixtures. then the only room i found them in was my bedroom, which of course had all the clothing for me and my children in it. it turns out that they are a very hardy beetle. can go 7 years w/out water, go into suspended animation when there is no food, look dead when they are not, they eat woolen material and other natural fibers,dead plant material as well as some live plants, paper, dried animal material (dead mouse), feces, hair, feathers, they love grain, and eat dried wood (therefor can damage your home). all in all they are just plain awfull! in order to get rid of them you need to eliminate the food source but considering the feed off of everything an exterminator is the best bet.

16 jenny January 29, 2010 at 2:33 pm

this is NOT TRUE we were getting bites all over our bodies at night we just called the exterminator to inspect the bed. He tore the bed apart and found SPIDER BEETLES AND CARPET BEETLES that DO BITE they are NOT BED BUGS. so be very careful.

17 nobugsonme January 29, 2010 at 6:32 pm


Sorry, but this is not true.

We hear it is possible to be allergically sensitive to the presence of such a pest, which may cause skin reactions. But entomologists tell us you are not being bitten by carpet beetles and spider beetles. They aren’t designed for it.

It’s worth considering that you may have bed bugs or another biting pest present, in addition to the spider beetles and carpet beetles. This is always possible, since bed bugs are difficult to detect, and finding them may take a skilled pest pro hours. How long did yours search?

18 august April 21, 2010 at 6:36 pm

Do spider beetles travel with bed bugs? Seems related to me we have them in our bed and being bit by some thing.

19 nobugsonme April 22, 2010 at 12:41 pm

As I understand it, spider beetles have no symbiotic or other relationship to bed bugs.

Spider beetles also do not bite.

It is possible for some people to have an allergic reaction to the presence of insects (without being bitten) which may appear similar to a bite reaction.

It is also, of course, possible to have spider beetles and bed bugs (or another biting pest) and see the spider beetles but not the other pest. Bed bugs hide. Biting mites are tiny. Spider beetles do not hide and are likely to be spotted meandering around.

20 SHIRLEY LORDE May 2, 2010 at 2:49 am

Just woke up with a burning and itching sensation with two welts the size of a dime on my arms, turn the lights on and found a spider beetle in my bed. About four months ago I had the same problem and found a spider beetle ,so please tell me what they are doing to my skin.Right now its about twenty minutes since this happen, the welts is size of a half of dollar so please explain.

21 nobugsonme May 3, 2010 at 12:28 am


It is not unusual to have spider beetles in the home.

It is also possible to have an allergic reaction to the presence of any insect. They do not bite, but you could be reacting to their presence.

22 Sam May 17, 2010 at 9:53 pm

Three weeks ago I came home with nickel size bites from work. I couldn’t understand what the were, I looked around and found that they were caused by spider betteles. As I’m looking around in the other rooms, I’m noticing that they have eaten all the other spiders. The exterminator was there and said that they don’t bite, we got in a heated arguement because he was wrong. So if anybody thinks that spider beetles don’t penetrate your skin, you have another thing coming. I’m trying to find out more, please write if you know anything else about them. May 17, 2010

23 nobugsonme May 17, 2010 at 11:15 pm


Entomologists have assured us that spider beetles do NOT bite.

We hear it is possible to be allergically sensitive to the presence of such a pest, which may cause skin reactions. But entomologists tell us you are not being bitten by carpet beetles and spider beetles. They aren’t designed for it.

It’s worth considering that you may have bed bugs or another biting pest present, in addition to the spider beetles and carpet beetles. This is always possible, since bed bugs are often difficult to detect at the beginning of an infestation, and finding them may take a skilled pest pro hours.

24 Malin May 23, 2010 at 3:07 pm

I just had the exact thing happen! My initial thought was bed bugs despite no signs except the bites which, for the record, where not several in a row but one here and there every 5 or 6 days or so. Exterminator came twice and started talking about how he doesn’t think I’ve got bed bugs. Finally googled around today and realized that the creatures I’ve caught on the glue traps are indeed spider beetles – which my exterminator confirmed. But he also maintains they don’t bite. Well, they bite ME! And everything I’ve read above applies to me, so I think we still have a thing or two to learn about these beetles.

Pls, write back about how you’re getting rid of them!
Many thanks!

25 nobugsonme May 24, 2010 at 12:42 am


You are being bitten by something. You see spider beetles. If I were the betting type, I’d be willing to bet you don’t actually see spider beetles biting you. They are not designed to do so.

It is fully possible to have bed bugs or other biting pests present and not see them (yet).

You may also be having an allergic reaction to the presence of spider beetles, carpet beetles, or another pest. This can happen without actual bites taking place.

26 Lou May 24, 2010 at 3:04 am

Spider beetles do not bite and do not take your blood as do bed bugs, mosquitoes, fleas, ticks, etc.
Just because you have skin lesions and you see spider beetles (because they are obvious) does not mean that this creature has to be the one that is biting you. Or, for that matter, if your lesions are from the bites of insects or arachnids. There can be many reasons for skin lesions and many reasons therefore have to be ruled out. There are many allergens in the home; there are many health-related problems that can result in skin lesions. Not all skin lesions come from being bitten.
“beetle. can go 7 years w/out water, go into suspended animation when there is no food, look ” The only place where I found this statement was on Wikipedia. You can’t rely on this one source for data. Don’t know who wrote the Wikipedia article. The write-up is kind of strangely written, too. Most spider beetles take months for larval development and produce a few generations per year, adults live for months or a year.
“Do spider beetles travel with bed bugs? Seems related to me we have them in our bed and being bit by some thing.” Why associate both insects because you happen to have both in your home? Just because many insects are found in your home does not mean that they are interacting, both are just in your home at the same time. Carpet beetles are in your home (common name, not restricted to carpets), booklice are in your home (common name, not restricted to books), dust mites are in your home (common name, not restricted to all dusts), cigarette beetles (common name, not restricted to cigarettes) but it doesn’t mean that they travel with one another: they all happen to possibly be in your home. You are giving these insects many human qualities but they are not human and don’t behave like people. Sorry to be so blunt, but the discussions aren’t being productive, but just going off on speculative tangents.
In general terms, spider beetles are scavengers, larvae feed on many stored products, dead insects, rodent droppings, and many other items. They are not blood sucking insects.

27 Winston O. Buggy May 24, 2010 at 7:27 am

I gotta weigh in here on the side of entomology for all the good reasons stated by Lou and my own experiences with this little cutie.

28 David Cain May 24, 2010 at 11:36 am


I have encountered spider beetles on 3 occasions in the last 7 years in London and on each occasion the occupants of the room were convinced that they were being bitten by them.

It appears that you can get a “bite like” reaction from spider beetles in some situations but as others have said they do not bite. The solution is to clear them out of the area with a liberal application of elbow grease and the use of a vacuum cleaner so they are no longer present to induce the “bite like” response.

As I repeatedly say if you are getting bites or any reaction look for the physical signs of bed bugs, namely:

Live samples – can be difficult to find as they like to hide away when we are not sleeping

Cast skins – paper thin outer casings of bed bugs left behind as they develop

Faecal traces – small (most commonly) black marks that look like a felt tip pen bad on surfaces

Bites or “bite like” reactions alone are not a strong enough diagnostic tool to identify bed bugs, they can tell you there is a problem but not what the cause of the problem is.

Hope this helps and clarifies.

David Cain
Bed Bugs Limited

29 Lou May 24, 2010 at 9:24 pm

Infra red image of Gibbium aequinoctiale spider beetle

many specimens of Gibbium aequinoctiale spider beetle

macro shot of Gibbium spider beetle in stored food product

30 nobugsonme May 24, 2010 at 11:02 pm

Thanks, Lou, David, and Winston!

31 Doug Haynes May 25, 2010 at 11:47 am

The best way to get rid of spiders and spider beetles to kill the insects it consumes for food. The number of insects in your place will determine how many spiders are going to be present. Once their food source starts disappearing, then they will go away. You can also try natural oil fragrances, spiders hate the smell of essential oils, but they can be pleasant for humans.

32 Lou Sorkin May 25, 2010 at 1:59 pm

Not really. The spiders are better if left in your home since they do consume many insects. But that said, you can have very many pests in your home and the spiders that are there may never really find them and consequently not make a dent in the pest population, so actually removing the pests doesn’t really translate into keeping spiders out of your home or office or other place. Spiders may be coming into the home because they just got in and not looking for food items but for mates (males searching for females) or gained access and not really looking for anything. The insect pests such as bed bugs, carpet beetles are in such hidden areas that many of the spiders that are there never really get into those areas at all and never really feed upon them. Various ant species could be living in your home and certain numbers may be captured or captured in webs by some spiders, but that little number doesn’t really make a dent in the ant population. Certain spiders are small and not even noticed, but they also may not be capturing and feeding on any of the common pests species anyway.

33 mary July 4, 2010 at 3:11 am

I dont care what the experts say..spider beetles do bite. I have them in my house and wasn’t bitten until I was driving to work and felt a sting and under my shirt was a pesky spider beetle.

34 nobugsonme July 4, 2010 at 5:20 pm


It is possible to have an allergic reaction to the presence of any kind of insect, and I would not be surprised if this allergic reaction could feel like a “sting” to you. (Please read David Cain’s comment above dated May 24th, 2010).

However, my understanding is spider beetles are not designed to bite you.

35 chris July 12, 2010 at 1:25 pm

i’ve been treated for bedbugs,cockroaches and etc…. just recently.I also threw my boxspring away but still getteing bites on my body can anyone help me i dont know how to get rid of it and the pest control guy obvisly doesnt work so……?

36 nobugsonme July 13, 2010 at 6:42 pm

A knowledgeable and experienced pest pro is generally the best way to get rid of bed bugs. But most cases take 2, 3 or more visits to treat. Usually, you need treatment every 10-14 days until bed bugs are entirely gone. If you did not have repeat treatments at similar intervals, this could be the problem.

Please come to our active user Forums if you would like more support or suggestions.

37 Zak Sommerfield July 20, 2010 at 7:25 am


I have to say sorry but spider beetles DO BITE. I have had an infestation of them going over several years. I continually try to have them exterminated yet they keep coming back. As i live in a very old apartment building they must be based somewhere in the floors between apartments.

At first I thought I had bed bug and did all of the steps to eliminate them. But after the 3rd exterminator came saying I clearly did not have bed bugs I decided to believe them and accept that I only have spider beetles.

They often crawl into my bed and bite me. To test if they really were the culprits for all of the mysterious bites and welts I was getting I put on on my skin. Sure enough after a minute it bit me and I got a welt exactly what I was finding.

Well I have to say they are not as bad as bed bugs they are quite annoying. They also have super insect powers and can stay alive without water or food for years! I once put one in a glass of bleach. He lived for a week swimming around in the bleach!!!!!

38 nobugsonme July 20, 2010 at 10:29 pm


As I said in the comments above, it is possible to be allergically sensitive to the presence of insects (like spider beetles) which may cause skin reactions. This could even cause a welt on your skin after you placed an insect there, IF you are allergic to it.

But entomologists tell us you are not being bitten by carpet beetles and spider beetles. They aren’t designed for it.

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