Books are made from a variety of organic materials: paper, leather, cloth, glue, size and starch. As a result, they are an appetizing source of food for a wide range of pests. Rats, mice, silverfish, carpet beetle larvae, moths, termites, crickets and cockroaches will all feed on the organic material in books and, if left undisturbed, can do considerable damage to valuable collections. Infestation can be a serious problem and immediate action is required at the earliest sign. Delay simply gives pests time to damage material, to lay eggs and breed, and allows the infestation to worsen.
Rodents are attracted to environments that are dark, wet, dirty, cluttered and undisturbed, providing places for them to hide, scraps of food to eat and water to drink. Rats and mice rarely damage books inside the home, but they are attracted to untidy sheds and garages, and any material carelessly packed and stored in these areas is at risk. Rodents can be killed with traps and poisons, but it is safer to simply disturb their habitats by tidying and cleaning the infested area. If conditions no longer suit them, rats and mice will simply leave in search of a more appealing environment.
Insects are a common cause of damage to books and papers inside the home, and a number of species can create problems at both the larval and adult stages of their life-cycles. Like rodents, they are attracted to dark environments with a ready food source where they can feed, lay eggs and pupate undisturbed. Unlike rodents, however, insects are often tiny and can live in the cracks in bookshelves or inside books where their eggs settle in the gutters between the pages.
Among the most common insect pests are silverfish (Ctenolepisma longicaudata) and carpet beetle larvae (Attagenus unicolor or Anthrenus verbasci).
Silverfish graze selectively on the starch, sizes and coatings on paper, resulting in notching to edges, delamination and areas of loss. Their tiny eggs resemble black poppy seeds and can hatch at any time between two and eight weeks.
Carpet beetles damage books at the larval stage only (adult beetles feed on pollen and nectar), and they are attracted more to cloth covers than to paper. The larvae are reddish-brown in colour and up to five millimetres long, with stiff bristles covering the body surface. They thrive in environments where fragments of hair, skin, pet fur and insect remains provide a ready source of food (e.g. in dirty carpets).
Action should be taken at the earliest sign of insect infestation, such as fresh damage or sightings of live pests. Other indicators such as carcasses, shed skins or body parts, frass (droppings) or piles of dust or powder may be signs of previous infestation which is no longer a threat, but these are danger signs nevertheless and a careful inspection should be made.
If clear evidence of infestation is discovered, the following action should be taken:
- Isolate infested material from non-infested material immediately. If in doubt, treat all material as if affected.
- Take books and papers from shelves and thoroughly dust them, preferably outside. Brush book gutters carefully, page by page, to remove hidden eggs. Remove and brush book jackets and plastic covers. If this is done indoors, brush onto waste paper and then bag and discard the waste.
- Move or dismantle shelves and carefully dust and vacuum the site, including under rugs and carpets.
- Only reshelve books after thorough checking and cleaning.
Insecticides and mothballs are not recommended, as they can have harmful effects on human health as well as on books and papers. It should also be remembered that insecticides have little effect on insect eggs, which may hatch weeks after sprays have ceased to be effective. However, if the infestation persists a professional pest control company should be contacted.
The approaches to pest control favoured by conservators today are passive, preventive and non-toxic. If the preferred environment of a pest is understood (e.g. carpet beetles in dirty carpets or mice in cluttered sheds) infestation can be avoided or eradicated by wholly non-toxic means. Infestation is unlikely to occur if bookshelves and books are kept clean, surrounding floors and carpets vacuumed regularly, and food and drink are not allowed in the area. This is safer and often far more effective than using poisons.
To prevent contamination, any books acquired second-hand should be carefully checked for insects or eggs before being brought into the home and shelved.
For more information, visit the reCollections: Caring for Collections Across Australia website or read Urban pest control in Australia.
The material contained in this guide is for general reference only and should not be relied upon to change a legal or financial position. The State Library of Victoria does not warrant the accuracy or completeness of the information and disclaims all liability for any loss or damage that may be caused by reliance upon it.