How to Tell Whether Woodworm Is Active in Antique Furniture
Small round holes in antique furniture are commonly described as woodworm, but holes alone do not prove that insects are still active. They may record an infestation that ended decades ago. A careful inspection can help you recognise warning signs, protect nearby objects and decide when professional advice is needed.
What "woodworm" means
Woodworm is a general name for the larval stage of several wood-boring beetles. The larvae feed and tunnel within timber before adult beetles emerge, leaving exit holes. Species, timber type, moisture and local conditions all affect the appearance and risk.
Do not identify a species or choose a chemical treatment from hole size alone. Similar-looking damage can have different causes, and unnecessary treatment can stain furniture, affect finishes and expose people to pesticides.
Old holes versus active infestation
Old exit holes are common in antique furniture. They are not, by themselves, evidence of current activity. The most useful approach is to look for several recent signs together and monitor the piece over time.
Possible signs of activity include:
- Fresh, pale exit holes whose inner surfaces have not darkened with age
- Clean, light-coloured bore dust or frass beneath or inside the furniture
- New material appearing after the area has been carefully cleaned
- Adult beetles found on the object or close to windows during the emergence season
- Weak, crumbling timber associated with recent dust
- A documented increase in the number of holes
Historic holes tend to have aged, dirty or polished edges consistent with the surrounding surface. Old frass may remain trapped inside joints and can fall out when furniture is moved, so one small deposit does not automatically confirm activity.
The [Canadian Conservation Institute](https://www.canada.ca/en/conservation-institute/services/care-objects/furniture-wooden-objects-basketry/basic-care-furniture-objects-wood.html) identifies sawdust-like material beneath furniture as a possible warning sign and recommends isolating suspected infested furniture and seeking conservation advice. UK local-authority guidance likewise cautions that suspected infestation may require professional assessment; [Bassetlaw District Council's pest advice](https://www.bassetlaw.gov.uk/environmental-health/pest-advice/) provides a concise overview.
How to inspect safely
1. Choose a well-lit area
Inspect undersides, backs, drawer runners, feet, joints and unfinished interior surfaces. These locations may reveal activity that is less obvious on polished show surfaces.
2. Photograph and record
Take clear close-up photographs with a ruler for scale. Note the date, location and number of suspicious areas. Avoid marking the antique itself.
3. Clean the surrounding area
Gently remove loose dust from the floor or monitoring surface, without probing holes or abrading the furniture. Place clean white paper beneath suspect areas so new deposits are easier to see.
4. Monitor regularly
Check the paper and furniture at sensible intervals, particularly through spring and summer when adult beetles commonly emerge. Photograph any change. A monitoring record is more reliable than memory.
5. Examine the environment
Damp conditions increase the vulnerability of many timbers. Check for condensation, plumbing leaks, damp walls and poor ventilation. Do not store antique furniture in a humid cellar, shed or unheated outbuilding.
What to do if activity is suspected
Move the furniture away from other wooden objects if it can be done without causing damage. Do not drag it or lift it by a weak top, back or arm. If practical, isolate it in a dry area and prevent dust or insects spreading, but avoid sealing damp furniture in plastic for a prolonged period.
Contact an accredited furniture conservator or a competent timber-pest specialist. Give them your dated photographs and monitoring notes. Ask for a diagnosis, the likely extent of damage and the least invasive effective treatment.
Do not spray household insecticide into holes. Surface application may not reach larvae deep inside the timber, and solvents can mark polish, paint, gilding, upholstery and adhesives.
Questions to ask before buying
When inspecting a potential purchase, ask:
- Has the seller observed fresh dust or beetles?
- Has the piece been treated, when, and with what product?
- Is there a written treatment record?
- Has structural strength been assessed?
- Was the furniture stored in a damp environment?
- Can the underside and interior be inspected?
Old, inactive flight holes do not automatically make a piece undesirable. What matters is present activity, structural condition, treatment history and whether the price reflects the condition.
When specialist help is essential
Obtain professional advice when the piece is valuable, painted, veneered, upholstered, structurally weak, extensively attacked, or part of a larger collection. Also seek help if the source of fresh frass is unclear or activity continues after treatment.
For workshop restorations and practical furniture-repair videos, [watch and subscribe to Antique Repair Shop on YouTube](https://www.youtube.com/@AntiqueRepairShop).
Sources and further reading
- [Canadian Conservation Institute: Basic care of furniture and wooden objects](https://www.canada.ca/en/conservation-institute/services/care-objects/furniture-wooden-objects-basketry/basic-care-furniture-objects-wood.html)
- [Bassetlaw District Council: Pest advice](https://www.bassetlaw.gov.uk/environmental-health/pest-advice/)
- [Canadian Conservation Institute: Framework for preserving heritage collections](https://www.canada.ca/en/conservation-institute/services/preventive-conservation/framework-preserving-heritage-collections.html)