What Are These Tiny Bugs on My Window Sill?

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Dear Heather,
This summer, I noticed these tiny little gray bugs on my window sills in the kitchen and bathroom. They are so light and tiny. I have almost thought they were dust at times. Last week I diluted some bleach on a cloth and wiped down the window sills. That seems to have helped. I’d still like to know what these small insects are?

Why are these tiny bugs hanging out in my window?

How can I stop them? Will I need to see the wizard, or can you help?
Bugged in the Boondocks

First of all, I want to thank you for the evening I spent with phantom crawlies after wandering down the rabbit trail of mite and lice research.


Second to calm down any entomologists —no, spellcheck, I most certainly did not mean etymologist—out there, I do know that the term “bug” for zoologists and pedants applies only to the order Hemiptera.

I also know most of you probably don’t care. Anything that creeps, crawls, or flies with more than four legs is a bug. I get it. I’m just preventing an email or two. People can be quite persnickety, all you need to do is look at my inbox for proof. Y’all don’t hold back when you disagree with anything said here. It’s ok, if it isn’t polite, the delete button works just fine.

As we learn bout the possible kinds of bugs or insect pests that could be lurking in your window sill, we keep adding to this post. If you think you know what you have and want to learn how to get rid of the specific bug, click on the name to jump directly to the section on that insect or pest.

Your first suspect for tiny bugs on your window sill: booklice

Since the first characteristic you noted is that your tiny bugs are light in color and that they are not tiny, black jumping insects, my bet is they are booklice or a close relation to booklice.

Booklice, also spelled book lice. Would you be stunned to learn that booklice are not true lice?

Scandalous. The pest control world is all in a tizzy.

These harmless pests are also called psocids. I tried really hard, but I could not find any stock photography of these arthropods, so you are going to have to use your imagination: tiny, grey, lots of legs.

These little bugs feed on mold and fungi and thrive in humid (damp) environments. This is why they love windows, where condensation can collect.

Booklice tend to hang out in windows as well as in the books that give them their name. Since they feed on molds, you can get rid of them by reducing the humidity that encourages mold growth. Investing in a dehumidifier is one way to keep them from coming back.

As for the short term, when you wiped the window sills with dilute bleach, you probably killed their food source.

Your problem may be solved, at least in the short term.

How to get rid of booklice

To prevent the booklice’s return, you can regularly wipe down your window sills with an anti-fungal or use dilute bleach.

These tiny bugs are harmless so try not to stress too much about them. They aren’t causing any damage. They certainly aren’t pantry moths, and so they fall into that category of creature that we try not to think about too much.

Remember, they aren’t destroying your property (except in the most severe infestations), they don’t trigger allergies like dust mites, and they don’t bite like bed bugs (You can learn about bed bugs here). Booklice are almost always just a barely visible nuisance.

Did you notice I said ALMOST? I want to note that occasionally, with severe infestations, booklice can find their way into pantries where they can infest grains. In that case, you throw away the infested grains, air out the pantry, and store any new grains in air-tight containers. If you do choose to go the dehumidifier route, you will also cut down on your dust mite population, too. Dust mites love humid homes. How’s that for a two-for-one win?

What are these tiny bugs in my house?

So… you arrived here by Google Search and your little window bugs are not booklice? Don’t worry, there are more little bugs in and around your windows than just our friends the booklice.

Here are some other possibilities for tiny insects and other creepy-crawlies that you can find in window sills and other places and what you can do to get rid of the pests:

Carpet Beetles

If your tiny window bugs are about 3mm long, that’s less than a 1/4 of an inch, and have wings, you may be dealing with carpet beetles.

While the adults don’t do a lot, they can bite. Their bites aren’t harmful unless you are allergic, but I’m sure that’s still annoying. However, the females can lay eggs in your home and their larvae are very destructive once they get settled in. They can be difficult to evict.

Take a close look at your tiny window insects and decide if they look anything like itty-bitty ladybugs (not the same coloring) or really tiny beetles. You will want to check out this post on carpet beetles. You do not want to let these annoying bugs set up residence in your home. Mom and Dad may not be bad roommates, but the kids? Those offspring can do a lot of damage, even if they are quiet.

Clover Mites

A little red clover mite

If you squash the tiny bugs and they leave a reddish stain, they are most likely clover mites. Clover mites are a common, harmless but aggravating pest that also tends to invade windows, basement window wells, and sliding doors.

Clover mites are true mites and not insects.

They are closely related to spiders and ticks, but the good news is that they eat plants. So they won’t be snacking on poor Fido over there.

The bad news is that they can invade by the thousands when the weather changes. (They tend to head indoors when the plants die off in the fall.) You will also see movement in the early spring when their eggs hatch.

How to get rid of clover mites.

To prevent stains on your woodwork, vacuum these and call it good. Please don’t forget to empty the vacuum immediately (and then take the trash out), or you could end up with mites in other places. Clover mites like to travel and just like they went on an adventure and ended up in your house, they can crawl right back out of your vacuum.

Clover mites aren’t going to damage anything unless you squish them and stain something. Much like teenagers, they are just wandering around in search of food. This post has a little bit on the prevention of clover mites.

Biscuit Beetles

A tiny biscuit beetle on its back

Another possibility for your little bugs or tiny insect pests would be “biscuit beetles”. These guys are also known as the drugstore beetle.

This fun little pest is not related to pantry moths but has many of the same annoying characteristics.

The big difference between pantry moths and biscuit beetles is that the beetles (adult form) are attracted to light. This attraction to light brought them to your windows, you to Google, and then finally to me. Aww.

How to get rid of biscuit beetles

Refer to this post on pantry moths for suggestions on how to clean out your pantry and store your food to prevent future infestations.

You’ll need to do a very thorough cleanout of your pantry.

If you are of the, I don’t want chemicals in my home mindset. All food will need to be in tightly sealed containers, and you need to pull your refrigerator and other appliances out to ensure there are no hidden food sources for your little, unwanted roommates.

This includes a very thorough vacuuming (don’t forget to empty the vacuum). Your tiny new insect friends love all kinds of food sources, including pet food and…. I’m sorry to say leather. They have unfortunately expensive taste.

If you tend not to pay attention to details, you may want to call in a professional.

The good news is they don’t bite. The bad news is if you have an infestation, they can be hiding in many places in your home, so the cleaning will need to be thorough AND ongoing.


A springtail on a leaf

Finally, the last usual suspect would be springtails. These little jumping arthropods feed on decaying leaf litter.

But Heather, my jumping insect-like arthropod doesn’t look like that springtail.

Pump the brakes. Remember when I said I did some research? There are nearly 6000 kinds of springtails. That leads to a lot of variety. Do a quick Google Image Search for springtails and see what you come up with.

I kind of think that the Blue Giant Springtail looks a little bit like Appa from The Last Airbender and is almost cute.

If you use mulch near your house, they could be wandering around looking for more food. These things are also harmless but can be a major annoyance if they move into your house.

What to do if they are springtails

If you notice they congregate in a window, be sure to check for water damage as springtails are attracted to organic decay.

If you find water damage, consult a professional as water damage can get expensive quickly, and damage like that generally does NOT get cheaper when ignored.

If you have plants near your window, you may have fungus gnats. You would only suspect fungus gnats if your tiny window bugs are light grey AND they fly You can check out how to get rid of them here.

Phorid Flies

Do your tiny black or brownish bugs mostly run but are able to fly?

They could be phorid flies, also known as scuttle flies or, more disturbingly as 👀 coffin flies. These insects have a segmented abdomen and a hump on their back. They are very small, with the largest checking in around ¼ inch. Fun fact, this family of insects contain the smallest known fly, Neat.

Don’t panic.

Even with a nickname like coffin flies, having phorid flies in the window sill doesn’t mean it’s time to call in CSI. It could simply mean you have a lot of leaf litter decaying too close to the window, and the light at night attracted them inside. Or maybe, it’s really long past time for your teenager to clean out the dishes they stashed under their bed.

However, they also love things like sewage and drains that don’t get cleaned out. In fact, there’s a common household pest called drain flies that like to set up camp in rarely used drains. You’ll know drain flies by their black wings—there’s a link to that article at the end of this post

How to get rid of phorid flies

Get rid of any decaying food or trash in the house. That smell, no matter how faint, is ringing the dinner bell. Check the back of the pantry, behind the refrigerator and stove, for any food that could have gotten kicked where it doesn’t belong. If you live over a crawlspace, is there a chance that something crawled underneath your home and met an untimely end? It’s not a fun job, but that unwelcome guest needs to go.

Make sure you clean your dish sponge regularly, as that would make a fantastic spot to lay eggs. Check your fruit basket to make sure there’s not a rotten apple or orange hiding at the bottom, too. Have you started sprouting some celery? You may want to rinse out that jar/pot. The stalk may be rotting at the base, which would also attract flies. (I’ve had this happen a few times and still managed to sprout the stalk after rinsing away the part that has decayed.)

Suppose it’s likely that decaying leaf vegetation is the cause. Clear any leaf litter or mulch away from the window. Additionally, if the frame around the wood is wood, check to see if there is water damage to the sill or sash. If there is, you will want to address this issue quickly before it worsens. In the meantime, give the area wipedown with dilute bleach. (You can read about how to use bleach safely here.)

Are you still trying to figure out what little critters are bugging you? Here’s another post that might help, How to tell the difference between fungus gnats, fruit flies, and drain flies. (I don’t suggest reading this one while snacking.)

And if you are trying to get rid of house or horseflies. We’ve got help for that, too: How to get rid of flies.

Good luck!

Submit your questions to helpme@home-ec101.com.

A tiny bug on a window with a plant on the sill. Text overlay says what are these tiny bugs on my windows

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34 thoughts on “What Are These Tiny Bugs on My Window Sill?”

  1. They could be carpet beetles! We had them and only saw the little fuzzy larvae on occasion and the itty bitty beetles would show up in our windows in the spring. I guess they were attracted to the warmth. Just google carpet beetles and it’ll show you some pics of both stages of development. They’re kind of a pain to get rid of, but since they damage clothing, carpets, etc., it’s important to identify them and try. They also eat any natural fibers, even pet hair.

  2. @BeckyHale Like these? <a href=”http://www.flickr.com/photos/hedgerowmobile/212279967/” title=”carpet beetle a by hedgerowmobile, on Flickr”><img src=”http://farm1.static.flickr.com/58/212279967_4a3cd0231e.jpg” width=”259″ height=”223″ alt=”carpet beetle a”></a>

  3. I am getting a build up of dandelion florets in the corners of my home windows. They are not due to drafts and even after I vacuum them, the build up continues as if they were nests of some bug. Do you have any idea what bug could be causing this? I don’t see anything within these floret nests.

  4. I also am having this same problem in the bathroom and utility/wash room. I can sweep a pile up at night and they are right back the next day.  Most of them are dead when i sweep them up, only a few moving.  I looked up all the suggestions psocids, carpet beetles, clover mites, and springtails and they are not them.  I’m going to bag them up and let an exterminator take a look at them.  If anyone has any other ideas please inbox me at emilynicolewilkerson@gmail.com.  Thanks 🙂

    • Take them to your local county extension’s office. I bet they will happily identify the pest or point you in the right direction.

  5. If they are the same as my beetles they are not the very tiny ones that go on ground rice and the like my beetles are a sixteenth of inch long or smaller and are usual on their back but if they smell bleach they do soon get onto their feet and run not too fast but run. They have under their shell halves wings and can fly. I have only seen one fly. Their are now about 30 a day in my bathroom window and damp bedroom window so they only like damp north windows . This is the first year I have being problem with them . These are darker than grey but not jet black. Graham

  6. Hello, two days ago I found these bugs running around on the corners of living room pillows and on the corners of air conditioner. They are very very small. Smaller than a dot drawn with a pen. At first they looked black but when I looked them closely they are more dark brown. The body of the insects is flat and shiny. They run around flat surfaces mostly. I had a fury blanket next to the pillows they never climb up there, they always stay on non textured surfaces. I’ve been searching everywhere in internet and nothing close, to the bugs I have just described, came up. I don’t know what to do. And how to fight against them. Please help.

    • I have the same bugs I think. I first noticed them when my drain burst under the sink. They came running fr the water. They would jump into my cat’s water and congregate in a very small pile. If you find out what they are and what to do about them let me know.

  7. Ok so I have the same thing little tiny like ” that big are in my window sill:/ how to i know there not damaging my window?

  8. I have been having these tiny little black bugs on the window sill. They look like black pieces of dirt and they I see them on the curtain from time to time. I noticed tiny larvae on the window sills. I wiped them down with Clorox wipes. Where are they coming from?

  9. I have these bugs on my window sills and in my books nearby. When I read about book lice I thought this is it, however these bugs are in my bed that I recently moved next to the window and they bite like crazy. I thought for a minute I might have bed bugs. They are not bed bugs and I would be happy to know they are book lice. They are sometimes white and sometimes black and sometimes when I crush them they leave a red spot, which I assume is my blood. Any suggestions?

    • I hate to be the bearer of bad news but it sounds like you’re dealing with bird mites. Contact a PCO who specializes in bird mites. Many exterminators are misinformed or uneducated in these bird mites. They are a nightmare so please get help right away.

  10. I think I have clover mites as do many of my neighbors. It looks like there are tiny specks of black pepper on my window sills. We are all in new builds approx 12 to 15 month. Did not have them last year but then we did not have landscaping around our homes. Now we do. What if anything can be done inside and outside of the house to get rid of this annoyance. How long does this infestation last. Your help is appreciated. Thanks. 🙂

    • /clover-i-hardly-know-her/ has some tips for preventing them next year. Your best bet is to wait them out, they are a cool season mite that goes dormant when things heat up. (assuming you live somewhere that gets 80+)

      • I have woken up a few times covered in bites on my legs arms feet at first I was positive I had bedbugs because someone I let sleep here said she found out she had them after getting a couch from a friend I searched for days with a flashlight in the usual places that bed bugs would be I finally found these tiny little tan bugs that were so small I had to use a flashlight and a high powered magnifying glass to even find it. I cleaned everything and threw out pillows blankets clothes as I found one on a chair in my bedroom that I keep clothes on I was told to spray with alcohol so I did all that I also had a few books under the bed and on my nightstand I opened the books and there they were a lot of them after the physical and emotional drain on myself from not sleeping and just cleaning constantly I had terminex come they checked everywhere and didn’t find anything I than realized I had caught one and had it in a plastic bag so I showed it to him I had to actually put a magnifying glass up to it take a picture with my phone than blow it up he immediately Said they are definitely not bed bugs he Said he couldn’t tell me what it was he Said maybe some kind of mites. as I have a shed very close to my bedroom window where the headboard is and birds sit there a lot I searched on the internet and the closest I could see It looked like was. a book lice but I heard they don’t bite I do have mold in my basement as this is an old house and a few blocks from the beach I’m out of my mind they were in about 6 of my books and I threw them out now if they are book lice how do you get rid of them? I also have a cat he lays on the bed and he does go outside he has Been pulling his hair out to so I am very confused if they are bird mites or lice how do I get rid of them he is on his frontline though I guess my question wS I thought they were book lice cause I saw the picture and they were in a lot of my books in my room but some one on here Said they don’t bite and I woke up several times in a couple of weeks coveted in bites. Out of my mind please help …

        • Hello, your best bet would be to call your county’s extension office and ask for the best resources in your area. They will have a better idea of what pests are an issue geographically. If you have not been traveling recently, this is your best starting point.
          Good luck!

        • Ive been seeing the same bugs like kina transparent so. Tiny look like book bugs .. They bite! No doubt! Gor lil bites an my feet ankles. Legs gross man. I use windex seems to kill them . i see them hanging around my pool i mean right on the edging and i have an inground fiberglass white so i can see them gross man just gross! In the door ways window sills mostly outside i haven’t seen any inside. But i vacume every other day and alway use bleach and water when i mop. They prob dont want to come in lol. And i spray my bed after i strip it with a mist of windex on habbit cause all bugs seem to hate windex lysol disinfectant spray and i put rubbing alcohol and dab it on my shoes and flip flops. To keep them away. Hope this helps. Im going to ask my bug guy also cause its anoying just to keep up. And ill repost if i get any good news.

        • Hi it almost sounds like spider mites. I woke up several nights in a row with bites all over my stomach. We did slept with the windows always open. Whatever they were, I killed them. I used a commercial flea bomb.They never returned. We lived in Co at about 7K above sea level. Most biting insects can’t live at that altitude. Anyway, one flea bomb was all it took. Flea bombs kill a variety of insects. Just set one off in every room, come back at the end of the day and, no bugs.

  11. have hay in my window tracks and upon moving it find tiby light green woms. Some winows have then – some don’t. Keep coming back

  12. I recent moved and I had some pictures leaning against the wall beneath a window. As I was getting ready to hang them up (I don’t know what made me look) but seen a tiny whitish bug about the length of this dash -. I found two more on another picture and am terrified they are bed bug nymphs. But I checked my mattresses and haven’t brought any other used furniture into the house other than a wood bed frame.

  13. Hi,
    Recently I found very tiny elongated grey coloured creatures with an extremely flat body found along the sides of the wall and the sides of the ceiling. They are about 3/4 or 1 cm long. There are at least 20 or more of them, some individuals, some clustered. They do no harm but a sight to behold, and they seem to be dead. When I tried vacumming them they seem to be stucked to the wall or ceiling and seems to have wings. I wiped them off with a tissue paper. Those without wings look just like plain cement and when pressed, its nothing inside but leaves a trail of grey dust. This is my first time encountering them since I moved to a new flat where there are lots of greenery around.
    Appreciate a reply to my email address. Thank you. October 18, 2016.

    • Not sure if you have received a reply – but,I think you are describing what are commonly known as “silver fish” – they live and like damp spots and are often found in kitchens and bathrooms – they also feed on wallpaper paste ,so may be found anywhere – they are harmless as far as I know although are not particularly nice to have around – just kill them off – there is a spray or similar for them but I`ve only ever encountered one or two and after killing them have not seen any more … good luck.

  14. I have had and now having the same issue. 20 years ago we got BILLIONS of these tiny bugs. They started again 10 days ago. I cleaned and cleaned and sprayed everything and anything I can think of. I cant get rid of them. Are in every room and still coming but only from the north of our home where there are horses. I put a strong fan on every window and they come in from another place. I have to put a fan near me when I sleep or they crawl all over my face. They do not bite bit I have billions of tiny bugs to vacuum every hour. They are on the walls outside just coming in all day. Is weird because they are unpredictable. I can go look early in the morning and there are billions walking towards my home and none coming when its real hot or I ca go when it’s real hot and they are coming. I don’t know what to do. I think I’m going to eventually ruin my wood because of so much spraying and clorax and pine sol cleaning I’m doing. They look like tiny fruit flies and other times like tiny beetles. They seem to like heat. They don’t get on the food or drinks other than water. When I turn the outside grill on I see them crawling over the wall by the billions to get near the heat. They do die but then more just keep coming. Again we get this infestation about every 20 years. Please HELP!!

    • Where do you live ( please don’t give me your address on here just general idea; state,country, city, etc. )and do other people in your area have the same problem

    • I have the same problem, pest control said biscuit beetles, they started when I got new PVC windows 18 yrs ago. There not loads but every day there on my window ledges ,we cleaner every day.many thanks


  15. I have these tiny black bugs, about the size of a flea, in my windowsill. I see many dead bugs but some are live and crawl out to my bedspread and I have found dead bugs and eggs on my clothes in my closet and in my drawers. They are only in my bedroom and not anywhere else in the house. I do know they are coming in through the tiny cracks of my window. What kind of bug is this?

  16. I think I have spring tails! Very frustrating because we just moved into our new house. I clean them and they just keep coming back all over my kitchen! They are usually dead when I clean them but are a few I see alive and they jump, they are very tiny!! How do I get rid of them!??


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