Booklice are not head lice. Penn State Extension and the University of Minnesota Extension describe booklice as small, wingless household insects that live in damp indoor places and feed on mold and fungi, and Penn State Extension adds that they do not bite. The CDC describes head lice as parasitic insects that feed on human blood and usually live on the scalp. A booklice finding does not answer a hair question: the CDC says finding a live nymph or adult louse on the scalp or hair is the best way to diagnose head lice.
Below, the two insects sit side by side, followed by what booklice look like, whether they can be in hair, where they come from, how to get rid of them, how to get a household insect identified in Pennsylvania, and the hair check itself.
Booklice vs head lice at a glance
| Question | Booklice | Head lice |
|---|---|---|
| Where do they live? | Indoors in humid, damp, generally dark areas, and in damp, warm, undisturbed places where mold and fungi are growing (Penn State Extension; University of Minnesota Extension) | Usually on your scalp (CDC) |
| What do they eat? | Molds and fungi, plus grains, insect fragments and other starchy material, including glue from bookbindings (University of Minnesota Extension) | Human blood (CDC) |
| Do they bite people? | Penn State Extension says booklice do not bite | The CDC describes head lice as feeding on human blood |
| How big are they? | 1 to 2 mm (Penn State Extension) | Adults 2 to 3 mm, about the size of a sesame seed (CDC) |
| Do they have wings? | Wingless (Penn State Extension; University of Minnesota Extension) | The CDC says head lice move by crawling and cannot hop or fly |
| What do you do about them? | Reduce the moisture in the room (University of Minnesota Extension; Penn State Extension) | Check the hair and scalp for a live louse (CDC) |
Every line above comes from Penn State Extension on booklice, the University of Minnesota Extension on psocids, and the CDC on head lice. Penn State Extension also says booklice are indicators of high humidity or moisture, which is the part that matters once you know what you are looking at.
What do booklice look like?
Penn State Extension describes booklice as small, soft-bodied, wingless insects, 1 to 2 mm long. It describes their color as light to dark tan, and says they can also be grey, dark brown, orange-brown or nearly clear. Because of their flattened appearance, Penn State Extension says booklice are sometimes confused for bedbugs, so if that is the worry in your house, start with head lice or bed bugs. The University of Minnesota Extension also describes booklice as wingless insects that can be found inside buildings.
Put that beside the head lice description and one thing stands out. The CDC puts an adult head louse at 2 to 3 mm, about the size of a sesame seed, and Penn State Extension puts a booklouse at 1 to 2 mm. Those two ranges sit right next to each other. Size alone is a weak way to tell the two apart. Where you found the insect is the more useful clue: a bookshelf, a damp basement corner or a bag of flour points one way, and a scalp points the other.
Can booklice get in your hair?
Neither extension service describes booklice living on a person. Penn State Extension says booklice do not bite, are not vectors of disease, and do not otherwise impact human or animal health. The University of Minnesota Extension says booklice are rarely damaging inside homes and are harmless to people or pets. Both describe them in damp indoor places feeding on mold and fungi: Penn State Extension in humid, damp, generally dark areas, and the University of Minnesota Extension in damp, warm, undisturbed places where mold and fungi are growing. Neither page describes a scalp as that kind of place.
Head lice are the insect that lives on people. The CDC describes head lice as parasitic insects that feed on human blood and usually live on your scalp. That is their food and their address, which is why a question about hair belongs to them rather than to the insect on the shelf.
If you want to see what the other insect actually looks like before you decide what you saw, here is what a live head louse looks like up close.
Are booklice the same as head lice?
They are not the same insect, though the shared name is not an accident. Penn State Extension places booklice in the order Psocodea, which it describes as booklice, barklice and parasitic lice. So the scientific grouping is real. What it does not mean is that the two live the same way. Booklice are wingless household insects that feed on molds, fungi and starchy material in damp places. Head lice are parasitic insects that the CDC says feed on human blood and usually live on your scalp. Nothing on the Penn State or University of Minnesota pages suggests that booklice turn into head lice or cause them. Body lice are another similar-sounding name: how body lice differ from head lice. And for the pet question, the CDC says animals do not get or spread head lice.
Where do booklice come from?
The sources place booklice in damp spots inside the building, not on people. The University of Minnesota Extension says that in homes, psocids typically are found in damp, warm, undisturbed places where mold and fungi are growing, and that people commonly find them during summer. It also says they are called booklice because they are often found near books or paper, and that booklice usually feed on molds, fungi, grains, insect fragments and other starchy material, including glue from bookbindings.
Penn State Extension describes the same picture: indoors, booklice are found in humid, damp, generally dark areas, feeding on mold growing on paper, books, wallpaper, flour or grain. Penn State Extension also says booklice are indicators of high humidity or moisture, and that they do not directly damage paper products or fabric. That is the practical takeaway for a parent. The insects are a sign of the damp, which is why the fix below is about the room rather than the books on the shelf.
How do you get rid of booklice?
The extension sources put the work on the moisture in the room. The sourced steps are short:
- Ignore small numbers of psocids, says the University of Minnesota Extension.
- If they are numerous, reduce moisture. The University of Minnesota Extension calls that the most effective method to manage booklice.
- Use a dehumidifier or fan to air out rooms and keep the air moving (University of Minnesota Extension).
- Store boxes, bags, books and papers off the floor to minimize exposure to dampness (University of Minnesota Extension).
- Aim lower on humidity. The University of Minnesota Extension says psocids do not survive when humidity falls below 45 to 50 percent, and Penn State Extension says lowering the relative humidity to less than 50 percent will prevent mold growth and booklouse development.
- Deal with the water itself. Penn State Extension says the best control in most cases is to remedy the underlying water issue that is allowing them to reproduce and persist.
The University of Minnesota Extension also says insecticides are normally not necessary, so this is a home-maintenance job rather than a spraying job. And neither extension page describes treating a person or a child’s hair for booklice. The work stays on the room: the damp corner and the air moving through it.
Does finding booklice rule out head lice?
Finding booklice does not rule head lice in or out. The CDC says finding a live nymph, which is a baby louse, or an adult louse on the scalp or hair is the best way to diagnose a head lice infestation, and that a fine-toothed louse comb may help you find lice. That is a look at the hair, not a look at the room.
The CDC also says nits are often confused with other particles found in hair such as dandruff, hair spray droplets and dirt particles. If that is where you are standing right now, here is how to tell whether a white speck is a nit or dandruff.
So the two findings do not speak to each other. Identifying the insect in the room is useful and worth doing. It just will not tell you what is or is not in your child’s hair, and a room with no booklice in it will not tell you either.
Getting a household insect identified in Pennsylvania
If you want a name for the insect you found, Penn State’s Department of Entomology will look at a picture. Lice Lifters of Bucks County does not identify household insects, so this is the right desk for it. Its instructions for insect identification requests say still photographs are preferred, because they have higher resolution than videos, and ask you to include details that will help with the identification. The department also asks people not to send samples that are removed from the body or contain bodily fluids. Penn State Entomology says samples from Pennsylvania residents receive priority, and that digital samples are typically handled within one business day.
- A clear still photo rather than a video.
- Where you found it, including the room and the surface.
- Why you are asking.
A name for the insect turns a vague worry into a specific chore. If the answer is booklice, that chore belongs to the humidity in the room.
When the concern is on your child’s head
If your question is about your child’s hair and scalp, that is a separate question from the room, and it gets its own look. A trained person can check the hair and scalp and tell you whether a live louse is there. If it is lice, Lice Lifters of Bucks County can remove them in one visit, and you can book a head check at Lice Lifters of Bucks County or read about professional lice treatment first.
For more on how a professional check compares with a home look, see what a professional lice check catches that a home look misses. For treatment, the CDC’s head lice information and your child’s doctor are the place to start, and questions about a specific medicine or dose belong with your pharmacist or your child’s healthcare provider.
Frequently asked questions about booklice and head lice
Do booklice bite people?
Penn State Extension says booklice do not bite, are not vectors of disease, and do not otherwise impact human or animal health. The University of Minnesota Extension calls them harmless to people or pets. Their food is mold, fungi and starchy material. If something does seem to be biting someone in your house, that is a separate question for a healthcare provider, and it is not a conclusion to draw from insects on a shelf.
Are booklice the same as bed bugs?
They are different insects, but the mix-up makes sense. Penn State Extension says that because of their flattened appearance, booklice are sometimes confused for bedbugs. Penn State Extension puts booklice at 1 to 2 mm and describes them feeding on mold and fungi in humid, damp, generally dark indoor areas. If bed bugs are the real worry, a photo sent through Penn State Entomology’s instructions is the way to settle what you found.
Do pets get head lice?
The CDC says animals do not get or spread head lice. Fleas are a different question: here is whether fleas can live in human hair. Booklice, for their part, are harmless to people or pets, according to the University of Minnesota Extension.
Should I treat my child’s hair if we found booklice at home?
Look at the hair before you treat anything. Neither Penn State Extension nor the University of Minnesota Extension describes treating a person for booklice; both put the work on the moisture in the room. And the CDC says finding a live nymph or adult louse on the scalp or hair is the best way to diagnose head lice. So the shelf is not the evidence here. The hair is.
Can a photo tell me whether my child has head lice?
For the insect in the room, a photo is the route: Penn State Entomology says still photographs are preferred, because they have higher resolution than videos. A scalp works differently. The CDC says finding a live nymph or adult louse on the scalp or hair is the best way to diagnose head lice, which means someone has to look through the hair itself. Penn State Entomology also asks people not to send samples removed from the body.
Can Lice Lifters tell me what insect I found in the house?
Not that one. Lice Lifters of Bucks County does not identify household insects. Penn State’s Department of Entomology does, and its instructions ask for a still photograph plus details that will help with the identification, with samples from Pennsylvania residents receiving priority. Our side of this starts at the point where the question is about a person’s hair and scalp.
Two findings, two places to take them
Two findings, two destinations. The insect from the room goes to Penn State Entomology for a name, and then to a dehumidifier, a fan and whatever is staying damp. The hair and scalp question gets a look of its own, so book a head check, and if it does turn out to be lice, professional lice treatment is the next step. One answer does not stand in for the other, and you do not have to settle both tonight.
