Woodlice Bait Traps

An adhesive surface, sometimes with a lure, placed on the routes woodlice travel. They catch and hold what walks onto them, which reduces numbers indoors and shows you where they are getting in.

Along the routes rather than in open space: hard against skirting boards, at door thresholds, under sinks, behind appliances, in cellars and utility rooms, and near air bricks or where pipes enter a wall. Woodlice follow edges and come in from outside, so traps near entry points tell you the most.

The traps contain no insecticide. The adhesive is the thing to plan around - place them out of reach, usually under or behind something rather than in the open. Cooking oil releases the glue if a pet does get stuck.

Typically several months, though a trap loses its tack once the surface fills with dust or dries out, which happens faster in a damp cellar. Replace when catches drop off rather than when it looks full.

No, and it is worth being clear about that. Woodlice live outdoors and walk in - traps catch what has already got inside, but do nothing about the population outside the wall or the gap they use. Traps plus proofing is the combination that works.

Vacuum them up and empty the vacuum outside, well away from the base of the wall. For the usual case - a group in a cellar corner or by a door after wet weather - that is the whole job, and it needs no insecticide. Emptying it outside rather than into a kitchen bin matters, since anything still alive walks straight back. Use traps afterwards to see whether more are still coming in.

Season and weather. Woodlice move indoors for shelter as outdoor conditions turn cold and wet, so autumn and winter is when most people notice them, and heavy rain pushes a wave in at any point. A jump in catches usually reflects the weather rather than a worsening problem.

Placement, usually. A trap in the middle of a floor catches very little, because woodlice travel along edges and under things. Move them hard against skirting, across the door threshold, and beside pipework. If well-placed traps stay empty while you keep seeing woodlice, they are coming in somewhere else - check air bricks and the base of external doors.

Yes. Traps catch what is already moving indoors, while a spray or powder treats the entry points and damp gaps they shelter in. Sealing the gaps and clearing leaf litter and pots away from the wall outside is what makes either last.

If woodlice keep appearing in numbers well inside the house rather than near doors and air bricks, the underlying problem is damp rather than pests, and a damp or timber specialist will usually be more use than a pest controller. If you do want pest control as well, look for a qualified pest controller with BPCA membership.