What's Eating Your Collection?

Further advice: Rodents, bats and birds

What should I be looking for?

Rodents:

  • Gnaw marks near the base of doors and cabinets.
  • Droppings and urine stains (note that mice are incontinent and leave urine wherever they walk). The droppings squash when fresh and become hard as they age.
  • Nests of shredded paper and textiles.
  • Paw prints and noise of scampering.

Bats:
  • Droppings (dry, crush to a powder and contain insect remains making the dropping “crunchy” and contain fragments that are shiny) and urine stains.
  • Food remains – insect wings.
  • Note that bat urine has a very pungent smell that will catch in the throat.
  • Bats may be seen flying at dusk.

Birds:
  • Droppings. These usually are whiteish and have a smeary appearance.
  • Nests of twigs and plant material.
  • Feathers and dead birds.
  • Noise of fluttering or bird calls.

Note that bats are a protected species and thus legislation governs what you are able to do in areas where bats are present. If you suspect that you have bats you must not use insecticides in the area. You should also remove all standard blunder traps as bats can get stuck on these traps and this may lead to prosecution. Contact Natural England for advice.


Why are these animals a problem?
  • Rodents damage building fabric and objects by gnawing. They may gnaw electrical cables causing disruption to supply or fire.
  • Bat urine is very acidic and this may result in staining or damage to objects. They may also disrupt the use of the site as areas that contain roosts may need to be avoided.
  • Bird droppings stain objects and may cause damage, particularly to stone. They also harbour insects in their nests and dead birds act as a food source for insects.

What can I do to limit damage?
  • Prevent these animals from entering by proofing the building – cap chimneys, fit metal mesh to vents and around pipes and in eaves.
  • Fit netting or spikes to bird roosting sites. Take care to ensure that birds cannot roost behind spikes as these often prove to be favourable nest sites.
  • Ensure that exterior drain covers are in good condition and fit well.
  • Doors can be fitted with bristle strips. If there is evidence of gnawing, metal cladding can be fitted to doors but this may not be acceptable for the aesthetics of the building.

Where can I get further advice?

Pest Management a Practical Guide. David Pinniger. Collections Trust 2009.
Pest Management in Museums, Archives and Historic Houses. David Pinniger. Archetype Publications 2001.
Bats in Traditional Buildings. English Heritage 2009. Available free from English Heritage. Product code 51454


Who can I ask?

Jane Thompson Webb, Collection Services Manager, Birmingham Museum and Art Gallery.
Jane_Thompson-Webb@birmingham.gov.uk

Care of Collections Group. If you are a member of Icon (Institute of Conservation), you can log onto the group forum and post a question in the Care of Collections (CCG) area. If you are not a member, you can send a question to the office and ask them to forward it to the group on admin@icon.org.uk 

Museum Development Officers or your MLA. 

Pest Control Companies. If you don’t have a relationship with a pest control company, the British Pest Control Association may be able to help and they maintain an accreditation system for pest control companies. Look for the letters BPCA. www.bpca.org.uk 

Natural England www.naturalengland.org.uk 

Bat Conservation Trust www.bats.org.uk or the Bat Helpline 0845 1300 228