Psocids are small insects which love moisture. In general, they need to live where humidity is high or moisture is present. Common places for psocid populations to thrive include window sills, under outside siding of homes, tree trunks, shrubs, flowers, around garden hoses, under bricks and rocks, around light fixtures and under boxes. However, some species will readily live in books, book cases, attics and crawl spaces. As stated above, there are many families and species of this insect and the science community has not quite come to a concise conclusion about how to group and name all that are included. Some appear to have specific moisture requirements and others do not. At the same time some seem to be food specific and others do not. To make matters more confusing, it appears that psocids are able to change their dietary needs as food availability changes. One thing is for sure: If you have psocids active in or around your home – expect them to prosper and keep coming back unless the conditions which they seek are changed.

Psocids hatch from eggs in about 2-4 weeks after the eggs are laid. Young will go through about 2-4 nymphal stages to reach adulthood which takes another 2-3 months. Once mature, females can generate 50-100 eggs during her life and as an adult she would expect to live 1-4 months. Most populations will produce 2-3 generations per year but there could be a lot more if conditions are just right. Psocids are able to adapt to their environment which will dictate just how fast they reproduce. In general, the more moisture and the more moderate the temperatures (50 -80 degrees) the more they will prosper. Cold weather (below 35 degrees) will kill off adults but eggs will live ready to hatch as soon as local temperatures get back to where they are comfortable.

Psocids will eat just about anything. Though most people think they eat books or paper, in fact psocids can thrive on a wide range of food. Such food includes cellulose (paper or books), book bindings, fabric (from which many book bindings are constructed), glue (the glue that binds most books has many natural components), any type of grain, mold, mildew, algae, fungus and other plant life. The fact that psocids will readily live in books is the same reason they will readily live on trees: the presence of both cellulose (paper is made from wood) and fungus or algae. Algae or fungus will readily grow in damp dark places inside homes but it also thrives outside. It is here where local psocid populations will begin to accrue. Once established alongside homes, they will commonly find adequate food supplies up underneath any type of siding on homes. From there they commonly find window sills to be great food areas as well as outside light fixtures, outlets, door frames, etc. The author has seen them thrive on just about any perimeter location of any structure which gets wet during rain or irrigation. Such areas have a tendency to harbor moisture and this harboring is what enables fungus and algae to grow. Once this growth starts psocids will soon follow.



The good news about psocids is that they are slow eaters. This means that damage from local populations is usually minor unless populations go unchecked for long periods of time. However, psocids are both annoying and persistent so most people don’t want them around. Fortunately, they are easy to kill and with the right products being used it is easy to manage or eliminate any activity in or around the home. First, there may be some maintenance needed in areas where activity is noted.

1) Mold, algae and fungus removal will help slow up psocids. Remember, this is a key food item for psocids so by cleaning away and removing that which they eat will cut down on their reproduction. DON’T CLEAN UNTIL AFTER YOU TREAT AND WAIT AT LEAST 2 WEEKS! If you clean before you treat, the net result will be that you’ll disperse the psocids making it harder to isolate their main nest and force them to forage elsewhere.

2) Reduce moisture. Though it is hard to stop rain from accumulating on window sills and other areas of the home, any attempt to channel water away and off structures will help to cut down on just how much fungus, mold and mildew can grow on and around the home. By cutting down moisture, you’ll be able to cut down on psocid activity.

Therm Humidity MonitorNow if you’re not sure of current moisture levels, get one of our HUMIDITY MONITORS. This portable device is an excellent tool for monitoring moisture in rooms and any area where pests like psosids are present.

Therm Humidity MonitorHumidity Meter:


3) Once mold, mildew and fungus has been cleaned away and moisture levels have been reduced, consider sealing any apparent cracks or seams through which psocids may be entering or living. IT IS VITAL THAT MOLD, MILDEW, FUNGUS AND PSOCIDS ARE ALL TREATED BEFORE YOU SEAL SO DON’T DO THIS UNTIL YOU’VE TREATED AS EXPLAINED BELOW AND THE PSOCIDS ARE GONE!! If you start to seal cracks without first addressing why they are wet, you will no doubt make a bad situation worse.

This will happen when moisture is sealed into siding and wall voids – a condition which many homeowners create when they randomly caulk.

The procedure to rid your home of psocids is simple:

  1. Treat the home (outside and inside) as explained below.
  2. Wait at least 2 weeks to pass with no psocid activity before you clean areas where psocids were active.
  3. Clean the areas as explained below.
  4. Let the cleaned area sit at least 2 weeks and only after you have at least a 2 week period with no psocid activity should you proceed with sealing cracks and crevices.


Pump SprayerRough and ReadyTreating the mold, mildew and fungus is the first part of controlling psocids. Once local populations have been identified, use a product like ROUGH’N READY. This product is easy to use and will kill off all mold, mildew and fungus on which the psocids live. Use a rag to wipe down window sills and other small areas but if you have a large area to treat, use one of our PUMP SPRAYERS to get fast and rapid coverage. Be sure to wipe the product all around insuring complete coverage any where psocids have been seen. This product should be used on siding, window frames and sills, around door frames and anywhere moisture is a problem. Psocids which are thriving in books or other dry areas won’t require such treatments; as stated above there are several species of psocids and several are able to live where mold and mildew are not present.

Rough and ReadyRough’n Ready:

Pump SprayerPump Sprayer:



PT-565 XLOOnce you have adequately reduced the mold, mildew and fungus on which psocids live, you have three types of treatment options. The one you choose should be made based on the type of surface being treated. If you have small areas to treat like a window sill or two, PT-565XLO will offer quick knockdown and ease of use. Because it is an aerosol, it won’t make a mess or require any time to dry. When used right it will go on dry and yet work immediately. PT-565XLO can be used on all books, record albums and any type of document or fabric as well. Again, proper applications will not damage the treated surface nor will it cause discolorations or any “wet or oily” film to be left behind. It doesn’t take much of this product to get good coverage and the more sensitive the treated surface, the less you should use. Remember, this product is for small areas and may require treatments every few days. This is because the active ingredient, Pyrethrin, offers no residual. In other words, it will only kill when it is being applied. Within an hour or so all the active ingredient will have broken down and be gone. For this reason you will probably have to make several applications if you want to get rid of all psocids since the treatment will only kill exposed or hatched insects. It won’t do anything for eggs so it is best to schedule at least weekly treatments for 1-2 months to insure you have broken the cycle altogether.

PT-565 XLOPT-565:


PT-Cykick AerosolPT-565 XLOIf you don’t want to treat quite as much than don’t use the PT-565XLO. Instead, use a slightly stronger formulation called CYKICK AEROSOL. This product has all the same qualities as the 565 with the one big difference in length of residual. This aerosol uses Cyfluthrin which will last 2 or more weeks per application. The advantage to this is simple: Less frequency of applications and less product needed. It too can be applied over surfaces like fabric and books without causing treated surfaces to discolor or get wet. Be sure to lightly apply it since a little is all that is needed when treating. The only draw back to this product over the PT-565 is that it will not flush the psocids. Since they will have to walk over treated surfaces to pick up a lethal dose it is imperative that you treat as many of the cracks and crevices in which the psocids may be hiding. Only then can you be sure to have proper coverage otherwise you risk reinfestation. One way to avoid this is to first apply the Cykick thoroughly and then followup with the PT-565XLO. The 565XLO will flush the psocids out of where ever they are hiding since they don’t like this product which in turn will cause them to walk over the surfaces treated with the Cykick which will then insure they die. This 1-2 punch is sometimes needed when you have a large area to treat which involves a lot of cracks and crevices.

PT-565 XLOPT-565:

PT-Cykick AerosolPT-Cykick:


Metered InsecticideAerosol DispenserLastly, a great option for use in offices, libraries and other rooms where there is a lot of paper is to install AEROSOL MACHINES. These are small, around half the size of a cigar box, and run on batteries. Inside the machines you’ll need to place small cans of aerosol which use a pyrethrin based active like the PT-565. Known as METERED INSECTICIDE, this aerosol will control a wide range of insects include psocids and can be used safely in the home, office, etc. on a continuous basis. Simply place a machine on the wall or bookshelf, set it to go off once an hour, fill it with a can of aerosol and you’re all set. Cans will last 30-45 days and batteries will last 6-12 months. This setup is the easiest of all since the machines will be doing all the treatments for you automatically. Essentially this takes away the human element which is prone to miss applications (usually due to time restraints, memory, etc.) and a common problem when using nothing but the PT-565.

Aerosol DispenserAerosol 1000:

Metered InsecticideMetered Air:



PT-565 XLOPump SprayerPT-Cykick CSIf you have large areas to treat which are outside like trees, shrubs, siding of structures, etc, the use of an aerosol product is not practical or efficient. For these areas it makes a lot more sense to use some type of liquid residual like PT-CYKICK CS. This odorless concentrate mixes with water and is applied with a PUMP SPRAYER over surfaces on which you have seen activity. It will provide both a quick knockdown and a long residual keeping hatching psocid eggs from thriving. PT-Cykick can be applied over the siding of homes, around windows, on trees and plants and just about anywhere psocid activity has been found. The advantage of this product over the aerosols is that you can do large applications quickly and your work will reward you with long residual. Remember, PT-565XLO will not provide any residual. Applications kill only when applied and immediately dissipate. The Baygon will last at least 1-2 weeks per application and if this isn’t long enough, use PT-Cykick since applications made with this product will last over a month. Remember, it uses water as the carrier so this product is not recommended to apply over books or other sensitive objects. Use the aerosol for such applications.

PT-Cykick CSCykick CS:

Pump SprayerPump Sprayer:

PT-565 XLOPT-565:


PT-565 XLOOnce you decide on which product to use remember to stay with it and make applications throughout the season as needed. Generally speaking, infestations which are located outside will be active in the warm months and go dormant if you have a winter. For the southern most states, it is not uncommon to have activity year round. Most of these outside applications should be done with PT-Cykick CS. If you have found psocids in the home or building and have decided to use one of the Aerosols, expect to do several treatments since these applications will not last as long. Aerosols by nature will break down much faster than the liquid treatment and in fact the PT-565XLO provides no residual. If using PT-565XLO you will need to do treatments at least once a week if not more until all eggs have hatched and the cycle has been broke. The Cykick Aerosol will last longer and should provide 1-2 weeks between applications which will reduce the amount of work you need to do.

PT-565 XLOPT-565:


Psocids can be a persistent and annoying pest in and around the home. Though they don’t bite, their chewing mouth parts can cause a lot of damage to fabric, books, wallpaper and other inanimate objects around the home which are valuable. Reduce moisture levels to deter nesting and seal cracks and crevices where psocids may be entering for long term protection. Treat with any of the products listed above for immediate control and elimination.


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Comments on PSOCID CONTROL Leave a Comment

November 18, 2012

Geri Schaff @ 2:42 am #


I think these are the bugs we have been battling for a month. We’ve tried spraying the entire bathroom floor with everything including bleach. Nothing is working! Which product would you recommend?

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