- Size
- Up to about 15 mm
- Look
- Grey, oval, armoured, 14 legs
- Needs
- Damp and shelter
- Risk
- Harmless
They're harmless. They don't bite, don't damage your home and don't spread disease. They're a useful clue that something nearby is damp.
Signs of woodlice
- Woodlice near back doors, patio doors and ground-floor skirting boards
- Woodlice in bathrooms, utility rooms or under sinks
- Dead woodlice in hallways and corners, usually dried out
- Woodlice around damp walls, leaking pipes or a damp-proof course problem
How to be sure
Woodlice are grey, oval and segmented, and some roll into a ball. Silverfish are silvery and wriggle, with three bristles at the tail. Carpet beetle larvae are hairy and banded.
What you can do yourself
- Sweep them up and put them outside. Indoors they won't survive long.
- Find the damp: check for leaks, condensation, poor ventilation, blocked air bricks or soil piled against outside walls.
- Seal gaps under doors and along skirting boards on the ground floor.
- Move compost bins, log piles, plant pots and leaf litter away from the walls of the house.
Call a professional if
- You suspect rising damp, a failed damp-proof course or a hidden leak. That's one for a damp surveyor or plumber, not pest control
- Woodlice keep appearing in large numbers despite drying the area out
Keeping them out
- Keep soil and plants below the level of the damp-proof course
- Fit brush strips under external doors
- Ventilate bathrooms and kitchens well
- Keep gutters and downpipes clear so walls stay dry
Kit that helps
- Door brush strips
- Sealant for skirting gaps
- Dehumidifier
- Extractor fan
Product types only. We'll only ever point you to things we'd use ourselves.
Questions people ask
Are woodlice harmful?
No. They don't bite or sting and don't damage sound timber or furniture. They feed on decaying plant material.
Do woodlice mean I have damp?
Often, yes. A steady stream of woodlice indoors usually points to a damp patch, a leak or an easy entry point from damp ground outside.
Should I use insecticide on woodlice?
It's rarely needed. Fixing damp and sealing gaps works better and lasts longer.