What Are These Tiny Bugs on My Window Sill?

Dear Heather,
This summer I have been noticing these itsy bitsy little grey 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

how to get rid of bugs on the windowsill

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.

They are harmless so try not to stress too much about it. They aren’t causing any damage 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.

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.

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.

clean windows

Click the picture for more tips!

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 flies naturally

Good luck!

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


  1. BeckyHale says

    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. HeatherSolos says

    @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. says

    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. barbLivefrye says

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

  5. Emily Wilkerson says

    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 :)

  6. graham says

    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

  7. Sona says

    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 says

      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.

  8. Peyton bieber says

    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. Ginny Rizzuto says

    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?

  10. Beth Greeney says

    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?

  11. R Mecca says

    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. :)

  12. elane Barry says

    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

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