What Insects Eat Paper? And How to Stop Them

Several groups of insects eat paper, and a few of them can do serious damage before you notice. Silverfish, firebrats, termites, booklice, cockroaches, and the larvae of certain beetles all feed on paper or the materials bound up with it. The reason is straightforward: paper is mostly cellulose, and cellulose is a sugar-based polymer that a surprising number of insects can break down and use for energy. Stopping them involves understanding what draws them in and making your environment hostile to their habits.

Silverfish and Firebrats

Silverfish are probably the most familiar paper-eating insect in homes and libraries. These wingless, teardrop-shaped insects belong to the order Zygentoma and have been around for hundreds of millions of years. They gravitate toward dark, humid spaces: basements, closets, bathroom cabinets, attics, and the backs of bookshelves. Their close relatives, firebrats, prefer warmer spots near furnaces, ovens, and hot-water pipes, but both species feed on the same things.

What makes silverfish and firebrats remarkable is that they produce their own cellulase enzymes in their gut, allowing them to digest cellulose without relying entirely on symbiotic microorganisms the way many other insects do. Research on the digestive systems of two Zygentoma species found that cellulase production stayed constant regardless of what the insects were eating, suggesting that these enzymes are always “on” rather than being triggered by a paper-heavy diet.¹ In practical terms, a silverfish does not need to be trained on paper to eat paper. Its digestive machinery is ready from the start.

Beyond cellulose, silverfish eat the starches in wallpaper paste, book-binding glue, and the sizing agents applied to paper during manufacturing. They also consume textile fibers, dead skin cells, and even other dead insects. So their attraction to your bookshelf is really about all of the organic materials present, not just the pages themselves. A recent species, the grey silverfish (Ctenolepisma longicaudatum), has become a particular problem in European libraries and archives, thriving in climate-controlled buildings and proving difficult to eradicate with standard approaches.²

Termites

Termites are the heavyweights of cellulose destruction, and paper is just a thin, conveniently stacked form of wood to them. Unlike silverfish, termites rely heavily on their gut microbiomes to break down plant material. A large-scale study that sequenced gut metagenomes across the full diversity of termite species identified hundreds of enzyme families devoted to carbohydrate metabolism, including multiple glycoside hydrolase families with cellulose-degrading activity found in more than 85% of species surveyed.³ This means that virtually every termite species on the planet carries the microbial toolkit to digest paper.

Subterranean termites, the most common structural pest in temperate regions, reach paper through mud tubes built along foundations, pipes, and walls. Drywood termites, more common in coastal and tropical areas, can infest a structure without any soil contact. In either case, paper stored near walls, in cardboard boxes on basement floors, or in neglected attics is vulnerable. Termites do not just nibble edges the way silverfish do; a colony can hollow out a stack of documents or an entire bookshelf from the inside, leaving the outer surface intact until the damage is catastrophic.

Some termites go even further than breaking down cellulose. Research on the Pacific dampwood termite and the Asian longhorned beetle demonstrated that these insects can degrade lignin, the tough structural compound in wood that most organisms struggle with. The termite’s gut showed evidence of lignin ring hydroxylation, a chemical transformation previously thought to require specialized fungi.⁴ Older papers made from poorly processed wood pulp contain residual lignin, which could make them even more digestible to termites than modern, highly refined paper.

Booklice, Cockroaches, and Beetle Larvae

Booklice (order Psocoptera, sometimes called psocids) are tiny, soft-bodied insects that thrive in humid environments. They do not eat cellulose the way silverfish and termites do. Instead, they feed on the microscopic mold that grows on paper surfaces in damp conditions. Their damage tends to be superficial, consisting of surface grazing that roughens and weakens paper over time. Still, a heavy infestation in an archive or storage unit signals a moisture problem that invites worse pests.

Cockroaches are opportunistic feeders rather than cellulose specialists. They chew on paper, cardboard, book bindings, and wallpaper paste, but they are equally happy with food scraps, grease, and organic debris. The damage they leave tends to be irregular, with ragged edges and dark fecal spotting. Cockroach excrement is acidic and can stain paper permanently, so even modest feeding leaves lasting marks on documents.

Beetle larvae account for the classic “bookworm” of popular imagination. Several beetle families are involved. Larvae of the common furniture beetle (Anobium punctatum) bore through paper and wooden book covers, leaving characteristic round exit holes when they emerge as adults. Drugstore beetles and cigarette beetles also attack paper, especially if it is stored near food products. Dermestid beetles (carpet beetles) are drawn more to the protein-based materials in book bindings, like leather and animal-hide glue, but their feeding often damages adjacent pages in the process.

What Makes Paper So Appealing

Paper is primarily cellulose, the most abundant organic polymer on Earth, and it retains many of the properties that make plant material attractive to insects. Modern paper comes in several varieties that differ in their vulnerability. Rag paper, made from cotton, has high-quality long fibers with a near-neutral pH. Acidic machine-made paper, the type mass-produced from the nineteenth century onward using wood pulp, has shorter fibers, residual lignin, and acidic chemicals, giving it an average pH around 5.2. Contemporary alkaline paper, made from heavily processed wood pulp with buffering agents, is closer to neutral at around pH 7.6.⁵

That middle category, the acidic wood-pulp paper produced for about 150 years starting in the mid-1800s, is especially vulnerable. Its lignin content gives insects more to work with, and its acidity accelerates chemical degradation, making the fibers weaker and easier to chew through. Starches, gelatin sizing, casein coatings, and plant-based adhesives used in bookbinding all add to the buffet. Even the glue on a postage stamp or the coating on a glossy magazine cover can attract feeding insects.

Humidity is the invisible ingredient that ties it all together. Paper is hygroscopic, meaning it absorbs moisture from the air. When relative humidity climbs above about 60%, paper surfaces can support mold growth, which attracts booklice and creates conditions that silverfish find ideal. Warm, humid environments also accelerate the chemical breakdown of paper, producing breakdown products that some researchers suspect make the material even more palatable to insects.

How Insects Digest Cellulose

For a long time, the assumption in biology was that insects could not produce their own cellulose-digesting enzymes and needed gut microbes to do the job. That picture has changed substantially. Studies across many insect groups have revealed endogenous cellulase genes, meaning the insects’ own cells produce enzymes capable of breaking down plant cell walls. A comprehensive review of the evidence concluded that this self-sufficient digestive ability may actually be the ancestral mechanism, predating the symbiotic relationships that termites and some other insects later evolved.⁶

Silverfish represent one end of the spectrum, producing cellulases endogenously and maintaining a relatively simple gut microbial community. Termites represent the other end, hosting elaborate communities of bacteria, archaea, and in some species, protists that collectively carry hundreds of different carbohydrate-active enzyme families.³ Most other paper-eating insects fall somewhere in between, combining their own enzymes with varying levels of microbial assistance. The practical takeaway is that cellulose digestion is deeply embedded in insect biology. Paper does not need to be rotting or weakened for insects to eat it; many species can handle fresh, intact fibers.

Recognizing the Signs of Damage

Different insects leave different calling cards. Silverfish produce irregular, shallow feeding marks with scalloped or notched edges, often concentrated on the surface layer of a page. They may also leave tiny dark droppings that resemble ground pepper, and their cast skins are sometimes visible in the crevices of bookshelves. Termite damage is deeper and more structural. You might find hollowed channels running through a stack of paper, mud tubes on nearby walls, or frass (fine, sawdust-like waste) accumulating below infested materials.

Beetle larvae leave round or oval exit holes, typically one to three millimeters in diameter, along with bore dust inside the tunnels. Booklice damage is subtle: a fine grazing of the paper surface that may not be obvious without magnification but produces a slightly roughened, matte texture on glossy pages. Cockroach damage looks messier, with irregular chewing and dark staining from fecal matter. If you find droppings or staining on paper with no visible feeding damage, the cockroaches may be eating food residues nearby and using your bookshelves as shelter.

Environmental Controls That Actually Work

Humidity management is the single most effective preventive measure. Keeping relative humidity below about 55% makes conditions uncomfortable for silverfish, discourages mold growth that attracts booklice, and reduces the moisture that accelerates paper degradation. A dehumidifier in a basement or storage area, combined with adequate ventilation, handles this in most residential settings. For archive-scale storage, climate control with consistent temperature and humidity targets is standard practice.

Temperature matters too, though mainly as a secondary factor. Most paper-eating insects prefer warmth. Firebrats in particular favor temperatures above 32°C (about 90°F), which is why they cluster near heat sources. Keeping storage areas cool, ideally below about 20°C (68°F), slows insect reproduction and metabolism. Air conditioning that also dehumidifies hits both targets at once.

Physical barriers are underrated. Storing important documents and books in sealed plastic bins or archival-quality enclosures denies insects access to the material entirely. Cardboard boxes offer no protection because they are themselves a food source. Elevating storage off the floor, even by a few inches on shelves or pallets, reduces the risk of subterranean termite contact. Sealing cracks around baseboards, pipes, and utility penetrations limits the entry points that insects use.

Good housekeeping removes the food and moisture that sustain insect populations. Regular vacuuming, especially in corners, behind furniture, and along baseboards, eliminates dust, dead insects, and mold spores that serve as supplemental food. Removing clutter reduces hiding places. And periodically inspecting stored paper for early signs of damage allows you to catch a problem before it spreads.

Monitoring and Early Detection

Sticky traps placed on floors near shelving, along walls, and in corners are a simple and effective way to monitor for paper-eating insects. In museum and library settings, this kind of trap-based monitoring is a core part of integrated pest management. Mapping where traps catch insects over time helps identify which areas have the highest activity and where bait or other interventions should be concentrated.² The same principle works in a home: a few inexpensive sticky traps behind a bookcase will tell you more than occasional visual checks.

For termites specifically, professional inspection is often necessary because the insects live inside walls or underground and are rarely visible in the open. Termite monitoring stations installed around a building’s perimeter detect foraging activity before the colony reaches stored materials. If you live in a termite-prone region and have valuable paper collections, periodic professional inspections are worth the cost.

Non-Chemical Treatments for Infested Materials

When insects have already infested paper or books, two non-chemical methods stand out for their effectiveness and safety. Anoxia treatment involves sealing infested objects in a barrier film and replacing the atmosphere inside with an inert gas, usually nitrogen or argon. The insects suffocate without any chemical residue left on the treated material. A study on infested choral books from a museum in Lima, Peru found that anoxia treatment achieved complete mortality across all insect life stages, stopping active damage without harming the paper or inks.⁷

Freezing is the other widely used non-chemical option. Placing infested items in a deep freezer at very low temperatures kills insects at all life stages, including eggs, which are often the hardest to eradicate. Research on pest-infested paper documents found that temperatures of −80°C can reduce the treatment time from several days to several hours while still achieving complete mortality.⁸ For home use, a standard chest freezer reaching −18°C to −20°C works too, but items typically need to stay frozen for at least 72 hours, and wrapping them in polyethylene bags before freezing prevents condensation damage during thawing.

Both methods are preferred by conservators because they leave no residue and do not alter the physical or chemical properties of the paper. They are treatments for active infestations, though, not preventive measures. Once the items are treated, environmental controls need to be in place to prevent reinfestation.

Why Chemical Fumigation Fell Out of Favor

For most of the twentieth century, chemical fumigation with substances like ethylene oxide was the standard approach for treating infested library and archival materials. Ethylene oxide is highly effective at killing insects, but the health risks eventually caught up with the practice. Chronic exposure to ethylene oxide increases the risk of leukemia, brain tumors, and other cancers, and may cause chromosome damage and reproductive harm.⁹

The problem extends beyond the fumigation chamber. Paper and other library materials absorb ethylene oxide during treatment and release it gradually over an extended period afterward. Curators, archivists, and researchers who handle fumigated items can be exposed without knowing it. The Library of Congress documented this desorption problem and noted that library personnel who routinely service fumigated collections face the greatest risk.⁹ This is a major reason why most institutional collections have moved toward anoxia, freezing, and integrated pest management rather than chemical fumigation.

Some targeted chemical interventions still have a role. Insecticidal gel baits, for example, have shown promise against grey silverfish in library settings, offering localized control without the broad contamination risks of whole-room fumigation.² Boric acid and diatomaceous earth, applied in cracks and voids where insects travel, can also reduce populations with relatively low toxicity to humans. These are supplementary tools, though. Without fixing the underlying environmental conditions that invited the insects, they provide temporary relief at best.

Protecting Specific Types of Paper

Not all paper faces equal risk. The acidic wood-pulp paper produced from roughly the 1850s through the late twentieth century is the most vulnerable, because it is both chemically fragile and contains compounds that insects find nutritious. If you have old paperback books, newspapers, or documents from this era, they deserve the most careful storage conditions. Acid-free archival folders and boxes provide a buffered microenvironment that slows chemical degradation and creates one more physical barrier against insects.

Modern alkaline paper is inherently more stable, but it is not immune. Silverfish will still eat it, and termites do not care about pH. Rag-based papers, including many art prints and high-quality stationery, are durable but still cellulose at the molecular level. The adhesives, coatings, and inks on any paper product can independently attract insects even when the paper itself is in good condition.

Photographs, which have gelatin emulsion layers over a paper or film base, are attractive to both silverfish and carpet beetles. Gelatin is a protein, and carpet beetle larvae in particular seek out protein-rich materials. Storing photographs in polyester sleeves inside sealed boxes protects against both insect access and the humidity fluctuations that accelerate chemical deterioration.

For anyone with a home library or personal archives, the hierarchy of protection is straightforward: control humidity first, provide physical enclosures second, monitor with sticky traps third, and treat individual infestations with freezing or professional help when they occur. Most paper-eating insects are not hard to discourage if you remove the conditions they depend on. The damage they cause tends to happen not because they are unstoppable, but because they go unnoticed in forgotten corners where moisture and neglect give them everything they need.