Stumbling across woodlice in your home or garden can be alarming – but the reassuring news is they're harmless, and getting rid of them is mostly about fixing the damp conditions they need. This guide sets out a safe, DIY-first plan to do exactly that. You may also want to bring their numbers down quickly to stop them breeding and leaving a noticeable trail.
The single most important thing to understand up front: woodlice are a damp symptom, not really a pest to spray. In our experience, the mistake people most often make is going after the woodlice they can see – with sprays or powders – while forgetting the root cause, which is the moisture drawing them in. Fix that, and the problem tends to resolve itself. We also see more woodlice indoors through the wetter, colder months, when they move in from outside.
📋 Quick answer: how to get rid of woodlice
Woodlice are harmless and thrive on damp, so drying out is the real fix:
- Dry the area: fix leaks and condensation, ventilate, use a dehumidifier if needed.
- Remove them: vacuum or sweep up visible woodlice (dispose of the contents outside).
- Remove damp hiding spots: clear leaf litter and rotting wood; unclog gutters; move pots and log piles away from walls.
- Seal entry points: proof gaps around doors, pipes and floor edges.
- Only if needed: use a woodlice-labelled powder or spray at thresholds and wall/floor junctions, following the label.
What Are Woodlice?
Woodlice are small crustaceans with oval, segmented bodies. They have a prominent shell-like exoskeleton and a pair of antennae. Typically grey in colour, they measure 10–15mm in length.
The name woodlouse comes from the words "wood" and "louse", a well-known parasitic insect – despite woodlice, which are crustaceans with 14 legs, being neither insects nor parasitic. Commonly known as slaters, sow-bugs and pill-bugs, they are harmless and primarily feed on decaying wood and other organic matter. Three main species enter our homes in the UK, with the pill woodlouse perhaps the best known for its ability to roll into a tight ball when disturbed.
Woodlice Behaviour
Understanding woodlice behaviour helps with identification and control. Here are the key aspects of their lifecycle and eating habits worth knowing.
Woodlice Lifecycle
Woodlice have a simple lifecycle, comprising egg, juvenile and adult stages.
Eggs: Female woodlice carry fertilised eggs in a small pouch on the underside of their bodies. The eggs hatch in the pouch, and the small, white juveniles stay there until they're big enough to survive outside.
Juveniles: Juvenile woodlice resemble adults but are smaller and lighter in colour. They grow through a series of moults, shedding their exoskeletons as they increase in size. Each moult happens in two stages: the back half of the exoskeleton is shed first, followed by the front a day or two later.
Adults: Adult woodlice are grey and measure between 10 and 15mm long. They continue to moult throughout their lives, which can last up to three or four years. In ideal (damp) conditions they reproduce rapidly, leading to larger populations. Their main predators include centipedes, frogs, toads, shrews and spiders.
What Do Woodlice Eat?
Woodlice primarily feed on decomposing organic matter. Their diet includes:
- Rotting wood: woodlice enjoy eating rotting wood, which is why you'll usually find them in dark, damp areas with plenty of wood debris.
- Vegetable matter: they feed on decaying leaves, plant stems and other vegetable matter.
- Other organic material: they'll also eat fungi, mould, mildew and even paper products if these are damp.
Are Woodlice Dangerous to Humans? Can Woodlice Bite or Spread Disease?
Woodlice are completely harmless and pose no threat to humans. They don't bite, sting, spread disease or damage possessions. They can chew the organic matter – decaying leaves and rotting wood – that they choose to eat, but they don't attack sound, dry timber or fabrics.
Where Do Woodlice Live?
Woodlice are most commonly found in dark, damp places, both outside and inside your home. Indoors, they turn up in basements, bathrooms, kitchens, cupboards and under sinks. Outside, you may find them under soil, rocks or logs, amongst plant debris or rubbish, and in compost heaps.
Where to Look First (Quick Check)
Woodlice nearly always cluster where it's cool, dark and damp. Check:
- Under sinks, behind toilets, and around baths and showers (silicone gaps, pipe entries)
- Utility rooms, basements and cellars, and behind washing machines
- External doors: thresholds, doormats, and wall/floor junctions
- Outside: leaf litter, compost, rotting timber, and blocked gutters or downpipes above the problem room
Identifying Woodlice Infestations
Recognising a woodlice problem early helps you take prompt action. Here are the key signs to look out for:
Physical Sightings
Woodlice are typically found in damp, dark areas such as basements, bathrooms and kitchens, or under rocks, logs and organic matter. Their distinctive appearance makes them fairly easy to identify.
Presence of Decaying Material
Check for signs of decaying wood, leaves and other organic debris, as these attract woodlice looking to feed.
Preventing Woodlice
Prevention is the most effective way to manage woodlice. If you want to get rid of them for good, focus on removing moisture and outdoor harbourage first, then block entry routes. Here are several effective strategies:
Reduce Dampness
Woodlice thrive in moist environments, so this is the single most important step. Use dehumidifiers in damp areas and make sure your home and garden buildings are well ventilated. Fix any leaks promptly, and ensure extractor fans in bathrooms and kitchens are installed and running smoothly.
Remove Infested Vegetation
Maintain your garden regularly, clearing decaying vegetation and organic debris such as cut grass, leaf litter, rotting wood and plant debris. Keep decaying organic matter out of reach in your kitchen too (for example, vegetable peelings).
Seal Entry Points
Inspect your home for potential entry points – cracks and crevices around windows, doors and pipes – and seal them thoroughly to keep woodlice out.
Natural DIY Woodlice Control
Natural methods are often preferred to chemical solutions. Just remember: with woodlice these are supporting steps – the drying-out described above is what actually resolves the problem.
Essential Oils
Certain essential oils, such as eucalyptus and peppermint, are thought to repel woodlice. Spray them around potential entry points, infested areas, or likely hangouts such as damp, dark spaces.
Diatomaceous Earth
Diatomaceous earth is a fine, food-grade natural powder that some people apply in dry cracks and along edges. One important caveat for woodlice in particular: it only works while completely dry and quickly loses any effect once damp – and woodlice live in damp conditions, so its usefulness here is limited. Drying the area out will always do far more. You'll find it in our natural powder range.
Sticky Traps
Sticky traps are useful for monitoring the level of activity and catching individual woodlice. They attract woodlice and other insects, which get stuck on the surface as they walk across. The limitation is that they don't tackle the source of the problem – the damp.
Chemical Solutions for Woodlice
If natural methods aren't enough or you need to act urgently, chemical treatments may help. Before using any chemical product, read the ingredients and potential side effects, and always follow the instructions carefully. Keep children and pets out during application, ventilate well, and only treat entry points and wall/floor junctions – not entire rooms.
Insecticides
Choose powders or sprays specifically designed for woodlice, which should be clear from the label. Apply them where woodlice are known to roam – entry points, damp dark spots and other hiding places. If you prefer to start gently, a food-grade powder such as diatomaceous earth is a lower-risk option around people and pets – just remember it needs dry conditions to be of any use, so it's no substitute for tackling the damp.
Cleaning and Repairing After Woodlice Infestations
Once you've dealt with the infestation, clean the affected areas and repair any damage.
Deep Clean
Vacuum and steam clean infested areas to remove any remaining woodlice, eggs or food sources. Pay special attention to cracks and crevices, where woodlice like to hide.
Repair Damp Areas
Fix water leaks and address damp promptly to prevent future problems. Replace or repair any wood or other materials that have been damaged by damp and rot.
When to Use Professional Pest Control Services for Woodlice
If you've tried to control woodlice yourself and can't get on top of it – for example, woodlice appearing in multiple rooms, an unlocatable damp source, or treatment proving ineffective – it may be time to call in the professionals. A good pest controller (or a damp specialist, since damp is usually the underlying cause) can offer tailored advice and solutions. You can find a qualified controller through the BPCA directory.
Woodlice FAQs
Do woodlice bite or sting?
No. Woodlice don't bite or sting people, and they're not known for spreading disease in homes. If you're seeing lots indoors, it usually points to a damp or moisture issue nearby.
Why do woodlice come into the house?
Woodlice need moist, cool conditions to survive. They often wander indoors from gardens and patios – especially through the wetter, colder months, and when there's condensation, a leak, damp flooring, or blocked gutters and downpipes making an area wetter than it should be.
Where do woodlice usually hide indoors?
In dark, damp spots, such as under sinks and behind toilets, in utility rooms and cellars, around external doors and skirting boards, and behind washing machines, fridges or kitchen kickboards.
What's the fastest way to get rid of woodlice?
Vacuum or sweep them up (dispose of the contents outside), dry the area (ventilate, fix leaks, reduce condensation), remove outdoor hiding spots (leaf litter, rotting wood, pots and logs against walls), and seal entry gaps around skirting, pipes and thresholds. If you still see lots after 1–2 weeks, consider a targeted, woodlice-labelled treatment at entry points (follow the label).
Will woodlice damage my home or eat wood?
Woodlice mainly feed on decaying organic matter (dead leaves, rotting plant material). They don't typically damage sound, dry timber. If you're seeing woodlice alongside soft, crumbling wood or persistent damp, it's worth checking for an underlying damp or rot problem.
I keep finding woodlice in my bathroom — what does it mean?
Bathrooms create moisture through showers and poor ventilation. Common triggers include condensation, gaps around pipework, or a slow leak. Run the extractor fan, open windows when safe, dry wet floors, and check the seals around baths and showers to reduce the damp conditions woodlice rely on.
How do I stop woodlice coming back?
Focus on prevention: fix leaks and reduce condensation (ventilation or a dehumidifier if needed), clear leaf litter and rotting wood and keep pots and log piles away from walls, unblock gutters and downpipes and improve drainage near the house, and seal gaps around doors, pipes and skirting boards.
When should I call a professional?
Get help if woodlice are appearing in multiple rooms, you can't find the damp source, or activity continues after 2–3 weeks of drying and proofing. Persistent woodlice usually mean there's ongoing moisture (a leak, condensation or damp) that needs addressing.
Final Thoughts
You can manage and prevent woodlice in your home by following the steps in this guide. Early identification and prompt action matter – but the key thing to remember is that woodlice are a sign of damp. Go after that root cause, not just the woodlice you can see: regular cleaning, removing dampness, and sealing off entry points will do the real work.
If prevention isn't enough on its own, consider a spray or powder, or seek professional help. Taking control of the conditions in your home is what keeps it healthy and pest-free.
We go to great lengths to ensure that all our DIY woodlice control products are effective, fast and easy to use. Explore our range to take control of your woodlice problem with confidence.
