Occasional Invaders

Every New England fall brings the overwintering parade: brown marmorated stink bugs, boxelder bugs, and western conifer seed bugs gathering on sunny south-facing walls, then slipping into wall voids to wait out winter. Spring and wet summers bring the moisture crowd — earwigs, millipedes, centipedes, pillbugs — all of which are really messages about conditions: damp mulch against the foundation, clogged gutters, humid basements. None of these damage the structure or bite meaningfully; they're nuisance pests whose numbers respond dramatically to exterior barrier treatment and moisture fixes.

Worth knowing

• Stink bugs that get into wall voids in October are the ones that appear, confused, in your living room in February — winter sightings are fall entries.
• House centipedes eat other insects — one in the basement is usually hunting something else on this page.
• Mulch piled against siding is the single most common invitation for the moisture crowd; keeping a dry gravel gap works wonders.