What Are These Tiny Bugs on My Window Sill?

Dear Heather,
This summer I have been noticing these itsy bitsy 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 sills. That seems to have helped. I’d still like to know what are they? How can I stop them? Will I need to see the wizard or can you help?
Bugged in the Boondocks

What are these tiny bugs in my window?


Heather says:

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. Blech.  Second to calm down any entomologists -no, spellcheck I most certainly did not mean etymologist- out there, the term “bug” for zoologists and pedants applies only to the order Hemiptera. I know you probably don’t care, I’m just preventing an email or two.

Since you noted that these were light in color and didn’t mention any jumping, my bet is they are booklice or a close relation. Booklice (book lice) are not true lice and are also called psocids. These little bugs feed on mold and fungi and require a humid environment. They tend to hang out in windows as well as in the books that give them their name. Since they feed on molds, reducing the humidity that encourages mold growth is the simplest way to control these tiny, harmless pests. Your wiping the sills with dilute bleach probably killed their food source and your problem may be solved, at least in the short term.

They are harmless so try not to stress too much about it. They aren’t causing any damage. They certainly aren’t pantry moths. and they fall into that category of creature that we just try to not think about too much. They aren’t destroying property (except in the most severe infestations), triggering allergies like dust mites, or biting like bed bugs. They are mostly just a barely visible nuisance.

These pests fall into that category of creatures that we just try to not think about too much. They don’t destroy property (except in the most severe infestations), they don’t trigger allergies like dust mites, or bite like bed bugs. They are mostly just a barely visible nuisance.

I do want to note that occasionally booklice can find their way into pantries where they can infest grains. In that case, you toss the infested grains, air out the pantry and store grains in an airtight container.

What if your bugs aren’t booklice?

Here are some other possibilities for tiny creepy crawlies in window sills:

If you squash the mites and they leave a reddish stain, they are most likely clover mites a common, harmless but aggravating critter that tends to invade windows. To prevent stains on your woodwork, simply vacuum these and call it good. Just don’t forget to empty the vacuum or you end up with mites in other places as they can usually crawl back out. Clover mites aren’t going to damage anything, they are just wandering around in search of food.

A guide to cleaning and caring for your windows

Finally, the last usual suspect would be springtails. These little, jumping arthropods feed on decaying leaf litter. 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. If you notice they congregate in a window be sure to check for water damage as they are attracted to organic decay.

Not a suspect here, but another harmless pest to be aware of is the fungus gnat. These guys love to chill in your potted plants. You can check out how to get rid of them here.

How to get rid of fungus gnats

Good luck!

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


  1. Dinah on June 17, 2017 at 10:30 am

    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!!

  2. Francesca Cheong on October 17, 2016 at 11:36 pm

    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.

  3. Kelly Champion on June 24, 2016 at 11:44 pm

    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.

  4. elane Barry on August 10, 2015 at 10:44 am

    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

  5. R Mecca on May 20, 2015 at 2:35 pm

    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. 🙂

    • Heather Solos on May 20, 2015 at 2:53 pm

      https://www.home-ec101.com/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+)

    • Ingrid on June 19, 2016 at 10:33 pm

      Thanks so much. The booklice sounds like what I have and makes sense. I brought home boxes of old books.

      • Pattynuzzello on July 24, 2016 at 3:08 am

        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 …

        • Heather Solos on July 25, 2016 at 4:49 am

          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!

        • Marie on June 15, 2017 at 11:01 pm

          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.

  6. Beth Greeney on June 20, 2013 at 7:30 am

    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?

    • Nobugsonme on November 18, 2015 at 11:41 pm

      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.

  7. Ginny Rizzuto on June 12, 2013 at 7:59 pm

    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?

  8. Peyton bieber on June 4, 2013 at 10:17 pm

    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?

  9. Sona on May 17, 2013 at 6:16 pm

    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.

    • Toni on April 21, 2014 at 8:28 pm

      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.

  10. graham on February 17, 2013 at 5:32 am

    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

  11. Emily Wilkerson on July 26, 2012 at 5:42 pm

    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 🙂

    • HeatherSolos on July 27, 2012 at 1:12 pm

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

  12. barbLivefrye on June 8, 2012 at 10:56 pm

    hi rich i guess ur watching, there are tiny nats on the windows they say to bleach them. what do u think?

  13. Wholesale Roses on February 25, 2012 at 3:22 pm

    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.

  14. HeatherSolos on July 11, 2011 at 2:20 pm

    @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>

  15. BeckyHale on July 11, 2011 at 10:21 am

    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.

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