Methods drawer
Exclusion & sealing
The cheapest pesticide is a sealed gap. Exclusion is the work that keeps working after every treatment has faded.
Most NW PA house pests arrive through a short list of holes: the gap under a door, the unsealed pipe penetration, the torn basement window screen, the siding joint opened by a winter of freeze–thaw, and the soffit gap where cluster flies and lady beetles pour in each October. Exclusion means finding those holes in the quiet season — late summer for the autumn invaders, early autumn for rodents — and closing them with materials the pest cannot chew or push: copper or stainless mesh behind sealant for gnawing pests, quality caulk for insect gaps, door sweeps that meet the threshold, and screens that actually fit.
How to do it well
- Work from evidence: droppings, webs, and traffic tell you which gaps are in use; seal the used ones first.
- Seal in the right order — exterior first, then interior — so you do not trap animals inside a wall.
- Never seal an active wasp entrance or a bat entry; both are special cases with their own rules and, for bats, legal protections.
- Re-check after the first hard weather: new gaps announce themselves.
Limits
Exclusion does nothing for a pest already breeding indoors — German roaches, bed bugs, and fleas arrive with furniture and luggage, not through the siding. And a house is a breathing structure: seal pest gaps, not the ventilation the building needs.