Woodworm – How to Identify and Get Rid of Woodworm in Furniture

You open the door of grandma's old wardrobe and see a small pile of pale dust on the shelf. Lower down, on the side of a chest of drawers, there are a few round holes the size of a grain of rice. First thought: did someone drill these? Second, much less pleasant: could it be woodworm?

"Woodworm" is the common name for the larvae of several wood-boring beetles that feed on dry wood in furniture, beams and joinery. Left untreated, it can turn a solid oak table into a hollow shell over the years. The good news: if you spot the problem early, you can save the furniture in most cases. In this guide we explain what woodworm looks like, how to tell if it is active and how to get rid of woodworm – with home methods and when the heavy artillery is needed.

What Does Woodworm Look Like at Each Stage?

Before you fight it, you need to know what you are dealing with. The life of these insects has four distinct stages:

• Egg – tiny, white or cream, about 0.5 mm long. Females lay them in cracks in the wood, so they are practically invisible to the naked eye.
• Larva (the "woodworm") – this is what does the most damage. White or cream, slightly C-shaped, with a hard brown head, 3 mm to over 20 mm long depending on the species. The larva bores tunnels in the wood for months or even years.
• Pupa – motionless, shaped like the adult beetle but paler and soft.
• Adult beetle – a small beetle, usually brown, black or dark beige, from about 2.5 mm (common furniture beetle) to 25 mm (house longhorn beetle).

Adult woodworm beetles are usually elongated and cylindrical. You will most often see one only briefly – in the evening as it emerges from a hole in the furniture, or dead on a windowsill.

Signs of Woodworm in Your Home

Most people never see a live beetle – they only see the traces. So how do you recognise woodworm even if no beetle has shown itself?

The key signs:

• Small round exit holes in the wood – 1–2 mm (common furniture beetle) or larger, oval holes of 5–10 mm (house longhorn beetle). These are where adult beetles emerged.
• Fine, pale dust (frass) under or around furniture, falling out of the tunnels.
• Quiet tapping at night – typical of the deathwatch beetle, which knocks its head against the tunnel walls to attract a mate, mainly in old structural oak.
• Weakened wood – the piece gives under pressure and sounds hollow when tapped.
• Dead beetles on windowsills, especially between May and August, when adults leave the wood.

A checklist worth running once a year, ideally in spring:

• check the undersides and backs of furniture – that is where attacks usually start,
• inspect joists, window frames and floorboards in older houses,
• examine inherited or second-hand furniture before bringing it into your home,
• vacuum around wooden furniture every few weeks – fresh dust will reappear if the infestation is active.

Types of Woodworm – and What Works Best Against Them

There are several wood-boring beetles you may come across in homes, and each needs a slightly different approach.

Common furniture beetle (Anobium punctatum) – the most common cause of woodworm in homes. Adults are 2.5–5 mm, with small round exit holes of 1–2 mm. It likes dry, older wood – furniture, floorboards and picture frames. The life cycle takes several years.

House longhorn beetle (Hylotrupes bajulus) – far more dangerous for the structure of a building. Adults are 8–25 mm with oval exit holes of 5–10 mm. It attacks softwood in roof timbers and joists, and its larvae can live in wood for many years – hence the scale of damage.

Powderpost beetle (Lyctus) – attacks fresh hardwood, mainly oak and ash, including parquet. Small holes (1–2 mm) and very fine, flour-like dust; it is often found in new floors made from insufficiently dried timber.

What works best depends on the scale of the problem:

• a few holes in one piece of furniture – woodworm treatment gel or spray, injected directly into the holes,
• infestation of a larger piece – fumigation, freezing or treatment by a furniture restorer,
• joists and roof timbers – always a professional woodworm treatment.

How to Get Rid of Woodworm – Effective Methods and Home Remedies

Can you treat woodworm without calling a specialist straight away? Home methods make sense for a small, contained infestation – one piece of furniture, a stool or a picture frame. The larger the area, the stronger the case for professional treatment.

How to treat woodworm at home:

• Woodworm treatment products from DIY shops (often permethrin-based). Inject into the exit holes with a syringe, then brush over the whole surface. Repeat after 2–3 weeks and always follow the manufacturer's instructions.
• Freezing – wrap smaller items (stools, drawers, frames) tightly in a plastic bag and put them in a freezer at –18°C for at least two weeks. This kills all stages of development.
• Heat treatment – in a professional heat chamber. Heat can crack wood, so this is best left to specialists.
• Replacing affected parts – in cabinet furniture it is sometimes easier to replace the back panel than to treat it.

Woodworm in a structural beam? Do not experiment – damage to a load-bearing element is not a job for home remedies. Call a timber treatment company to assess the beam and choose the right method.

Prevention is cheaper than cure:

• keep indoor humidity around 40–55% – woodworm prefers damp wood,
• finish wood with oil, wax or varnish – a sealed surface is less attractive to egg-laying females,
• inspect old furniture carefully before bringing it indoors, and if in doubt freeze it or have it treated.

FAQ

Is woodworm dangerous to people?
No. The beetles do not bite or sting and do not carry disease. They are only a threat to wood – but in structural beams this can eventually damage the building.

Where did woodworm in my home come from?
Usually from inherited or second-hand furniture, old window frames, firewood or a new floor made from insufficiently dried timber. Adult females can also fly in through an open window in summer.

Does fresh dust under furniture always mean active woodworm?
Usually yes – fresh, pale frass is a sign that larvae or beetles are still active. Old dust is darker and more compact.

Will shop-bought products work on a woodworm-infested joist?
Usually not. Beams are too thick for a spray to penetrate deep enough. Professional treatment is needed.

Can furniture with lots of holes be saved?
It depends on the structure. If the wood is soft and gives under your finger, saving it may not be worthwhile. With a few holes, treatment followed by filling with wax or wood filler is usually enough.

How long after treatment is the furniture safe to use?
After professional treatment, usually 24–72 hours of airing – follow the specialist's advice. After freezing, you can use the furniture once it has thawed and dried.

Old wood has a soul and history that no catalogue can recreate – it is worth fighting for. But when a piece really cannot be saved, choose its successor wisely. If you are looking for furniture that will serve you for years, explore the Pillovely collection.

Read next and shop the look

• Caring for furniture: how to care for wooden furniture and how to paint furniture.
• Shop dining tables, chests of drawers and wardrobes.