Introduction to pest management in museums
This page explains how to identify, monitor, and manage pest activity in your museum. It covers how pests enter collections, how to set up an Integrated Pest Management (IPM) programme, the most common museum pests and how to identify them, treatment options, and what to do during and after an outbreak.
Introduction
A museum pest is anything that can damage collections by eating, chewing, or leaving organic matter, bodies, urine, or droppings.
Keeping your collections and the spaces they are housed in pest free is an important part of protecting your museum environment. Good pest management helps prevent infestation, limits damage to buildings and collections, and reduces the loss of historic material. Not all pests are dealt with by museum staff. Rodents such as rats and mice may require an external contractor, as they can carry disease. Birds nesting nearby or on roof spaces may require specialist equipment or even falconers.
Bats can also cause damage through their acid urine and guano, which can stain, corrode, or etch surfaces and pose a possible health hazard. Bats are protected in Scotland, as are their roosts, so can not be treated as pests. If you have bats, NatureScot has guidance on best practice and licensing for exclusion.
Knowing which insects to be concerned about is the first step in planning for their management. English Heritage has produced a poster identifying the most common museum pests to help you get started.
What is integrated pest management?
Pest management is not new. The food industry has long used methods to identify, monitor, and control pests such as rodents, insects, and birds to protect food safety.
Museums have adopted a similar approach, focusing on prevention and using targeted, safe treatments to manage outbreaks. Staff need to understand why pests are attracted to buildings and certain collections, and look at outcomes rather than processes to minimise risk.
This holistic approach is known as Integrated Pest Management (IPM). Collections Trust has produced a video resource to help you get started.
How pests enter collections
Understanding how pests get into your museum helps you identify where to check for entry points and prevent access. Rodents come in through cellars or drainage systems. Insects, birds, and beetles fly in through open windows and doors, or enter through:
- Physical gaps in floorboards
- Defects in building fabric, for example cracks or loose roof tiles
- Chimneys, trapdoors, and drainage
- Ventilation systems
- Attics and basements
- New acquisitions, incoming and returning loan material
- Packaging on collections, shop stock, or items brought in as props or for workshops
- Deliveries and supplies
- Staff and visitors
- Plants or flowers brought in for events, display, or as gifts
- Specialist treatments, for example skeletal specimen preparation
Be sure that the building your collections are housed in is checked, cleaned, and maintained regularly.
Create a quarantine space
If you have space in your museum, set up a quarantine area than can be used to prevent pests from reaching your core collection. Choose somewhere secure and separate from stores and display areas where you can isolate objects that might harbour pests.
You do not need a large space. Having a procedure for checking material on arrival will significantly reduce risk. If you are uncertain about any new collection items, wrap or isolate them for a period of time.
How to monitor for pests
Pests don’t target every material in museum collections. Many collections do not contain the nutrients pests require. Pests seek food, shelter, or nesting spots within buildings and can graze through one item to reach the food source they want, which is mainly organic material. They also use collections for nests or bedding. In many cases, larvae cause the most damage, not the adult pest.
Museum pests can reside undisturbed, with larvae or grubs hidden within structures. Damage can occur before staff spot any pest activity, especially in little-used areas or during periods of closure.
Pests are not active all the time. Understanding their life cycles, the environmental or seasonal conditions that cause larvae to pupate and hatch, and how they move through museum spaces helps you target trapping, inspection, and housekeeping more effectively.
An IPM programme helps you instigate regular monitoring and checking. MuseumPest.net has policy and procedure templates to support this.
Finding pests early saves time and money compared to dealing with an escalated issue. Blunder traps designed to catch insects complement visual inspection. They help you see what might be in and around your collections. You can add attractants to traps, such as concentrated food or sex pheromones, to target specific species. Traps are a monitoring aid, not a solution to a pest problem.
Top tips for monitoring:
- Use blunder traps to catch insects and indicate any activity or presence
- Inspect traps regularly, prioritising spring and summer
- Record and identify finds, ideally quarterly
- Keep records and adjust housekeeping practice accordingly
- Ask all staff to report dead insects or rodents, frass or droppings, holes, or signs of grazing
Where to place traps:
- Anywhere you store or display collections
- Prioritise organic material, items of concern, and new acquisitions
- At floor level (or around one metre from the ground for moth)
- Along walls and under furniture
- In damper, dark, or undisturbed spaces where environments favour pest activity
- Under wool carpets or rugs
- In voids or areas where dust can build up
- On windowsills and near chimneys
- In cafes and any areas where people consume food
Know, record, and map what is present in your collections to help you construct a plan to remove and prevent further issues. Not all insects you find in museums are museum pests. Monitoring may reveal spiders, centipedes, woodlice, or flies. These do not eat collections, but their bodies are a food source for insects of concern and they can indicate a possible environmental issue.
Use wire mesh covers, adapted traps, or enclosed traps to reduce the risk of catching rodents or non-target insects on blunder or sticky traps.
Which pests affect museum collections?
Insects are small and hard to identify, especially if they have decayed or another insect has partly eaten them. Do not guess. Use online resources such as What’s Eating Your Collection? or ask a conservator.
Use a good light source and a magnifier or microscope to identify the species correctly. The type of damage on an item and the material it is made of can also indicate the pest. Look for frass (insect faeces), droppings, grazing, larvae casings, and the size and shape of any holes.
The most common insects of concern in museums are:
| Type of pest | What to look for | Control measure |
|---|---|---|
| Beetle | Beetles enter through windowsills, chimneys, or from attics, usually from bird nests or animal burrows. Several varieties can damage museum collections. Spider beetles (around 5-7mm): these resemble spiders but have six legs. The Australian (Ptinus tectus) and Golden (Niptus hololeucus) varieties enter buildings from bird or animal nests. They eat vegetable and animal debris and are particularly destructive to insect and plant specimen collections, though larvae also eat other organic material such as paper. Damage can resemble woodworm. Biscuit beetles, such as drugstore (Stegobium paniceum) and cigarette (Lasioderma serricorne) beetles (around 2-4mm): larvae eat dried food, plant material, and paper-based objects. They prefer material with a high starch content but do not eat wood. | Prevention is the best approach. Focus on housekeeping, building maintenance, and stable environments. For wood-boring beetles, use freezing or localised insecticide treatment. Quarantine collections if you find activity and monitor or treat other items in the same area. |
| Booklice | Booklice are very small, under 1mm in size. The common booklouse (Liposcelis bostrychophila) produces nymphs that resemble small, almost transparent adults. They prefer damp environments and feed on starchy food in books, paper, museum labels adhered with starch paste, or animal glue. Like silverfish, they also feed on microscopic mould. | Booklice prefer warm and damp conditions, as with silverfish. Manage the museum environment and carry out regular housekeeping. You can freeze and dry mouldy books and paper. Use pesticides only as a last resort, as the materials booklice tend to affect are often sensitive or damaged by such treatment. Cleaning and treating bookcases after removing objects can also help manage numbers. |
| Moth | Moths enter buildings through open windows or doors, or from bird nests in buildings or nearby trees. They are small, around 5-10mm long, and move in a skittering fashion, more slowly in cooler spaces. They prefer the dark and eat protein-based materials, favouring keratin in fur, feathers, skins, and hair, as well as fabric, especially soiled items. | Regular, focused housekeeping is the best approach, as moths do not like to be disturbed. Do not use mothballs or commercial moth treatments containing harmful chemicals. These chemicals pose a risk to human health and may cause chemical reactions with metals or materials in the object being treated. |
| Silverfish | Several varieties of silverfish (Lepisma saccharinum) affect museum collections, including common, grey, and long-tailed silverfish. Long and torpedo-shaped, around 10-15mm, they feed on organic material, starch, and mould on books, paper, archives, and occasionally textiles. Large numbers usually indicate high relative humidity. | Lower the relative humidity, as silverfish need moisture to survive. Use HEPA-filtered vacuums to remove mould spores, which silverfish also feed on. Remove unnecessary hygroscopic material such as old packaging, which retains moisture and provides a food source. |
How to treat pests without chemicals
If you cannot fully clean an item, or pests may be in areas you cannot reach, use low-temperature freezing. This is an effective, chemical-free, and cost-effective way to kill larvae and eggs.
If you have space and large amounts of organic material at risk, a chest freezer may be a lower-cost treatment option in the long term. After the initial purchase, train staff to pack collections for freezing so they know what you can and cannot treat in-house.
High temperatures (above 45°C) also kill insects. Heat treatment is faster than freezing, safe for humans, and relatively low cost, but carries a risk of drying the item, so weigh the pros and cons carefully.
Oxygen-depleting procedures using nitrogen or high carbon dioxide fumigation can also eradicate pests. Temperature affects the length of treatment, so this can take longer and may affect objects such as pigments. You must seal the item in an airtight enclosure, so use a specialist for large or complex items.
Parasitic wasps (Trichogramma) can target pests, especially moths. This is a non-toxic, sustainable option that kills larvae by laying eggs inside them. They work best at temperatures above 15°C and are limited in the species they target.
When to use chemical treatments
Where non-toxic treatments are not possible or appropriate, you can treat collections and spaces with chemicals in sprays, powders, vaporisers, or fumigants. Only use licensed products, carry out health and safety and risk assessments including Control of Substances Hazardous to Health (COSHH), and use competent practitioners.
Choose the right treatment method based on:
- What the object is made of
- The condition of the object and whether it needs pre-treatment
- The insect you need to control or eradicate
- How treatments will affect the object, people, and users
Always check with a conservator or specialist before implementing any procedure on collections. Use intervention only after more passive approaches have failed, or where there is an immediate risk of significant damage.
How to deal with a pest outbreak
At the first signs of an infestation, take these steps:
- Isolate and seal the affected items in a bag or wrap them in polythene, and label clearly
- Alert staff or visitors if required, in line with your written IPM or emergency plan procedures
- Identify the species and its life cycle. Bring in a conservator or specialist if you cannot identify the pest, or if you need a contractor
- Record the details, take pictures, and map where the outbreak occurred on your IPM documentation or room map
- Carry out treatment in line with best practice, using museum-approved treatments appropriate for the type of collection affected and in line with health and safety procedures
- Clean the affected area, follow disposal guidelines, and thoroughly clean all equipment afterwards to prevent cross-contamination or reinfestation
After the outbreak:
- Fix any issues, for example cap chimneys, seal cracks (wire wool in mouse holes in skirting deters mice), and remove vegetation from outside the building
- Check environmental conditions and address anything that favours pests, for example high relative humidity attracting silverfish
- Improve hygiene and housekeeping practice: keep food in containers, or remove food and drink from collection areas
- Review your IPM plan and put additional measures in place, for example adjusting trap locations, increasing monitoring, introducing spot checks, or changing operational practices
Health and safety during pest management
What staff need to know
Make sure all staff, including cleaning staff, know about your IPM programme, monitoring processes, and trap locations. Follow guidelines for mitigation, using non-toxic treatments as the first option and limiting the use of pesticides. Focus on housekeeping, freezing, desiccants, or anoxia treatment instead.
All staff must wear appropriate PPE and carry out risk assessments, including COSHH assessments, when dealing with an outbreak and any resulting treatment.
Build a culture of understanding around why eating or drinking in collection spaces is problematic. Make sure storage and waste disposal processes do not attract pests, rodents, or scavenging animals.
Working with pest control contractors
Make sure contractors on site are BPCA registered, do not apply chemicals to museum collections, do not use bait that could cause further insect infestation, and understand how to work in a heritage building. Ask them for documentation of pest inspections, trap catches, and any treatments they have carried out.
Supervise all contractors and make sure staff are available to help move collections to allow access, inspection, and treatment. Check that they use equipment that will not damage collections or the historic building. Carry out risk assessments for use of ladders or scaffolding when accessing hard-to-reach spaces such as attics, chimneys, and roofs.
Also consider:
- Health risks to others, for example if insects are swarming or guano is in public areas
- Risk to protected species such as bats
- Disposal of contaminated material and guano
- Hidden hazards in affected material being handled, for example arsenic or historic pesticides
Further Information
National Museums Scotland delivers annual training in IPM practices and has a pest desk to help identify insects or rodents. Their guide on How to deal with an infestation provides helpful step by step advice on discovering and managing an infestation in your collections.
The Institute of Conservation (ICON) have a collection of resources on pest identification.
The What’s Eating Your Collection? website is an introduction to integrated pest management and how to implement it in your museum.
Pinniger, D. (2008). Pest management: A Practical Guide. Collections Trust. ISBN – 9781900642170