Do this now
- If anyone is stung and has trouble breathing, swelling of the face or throat, or dizziness, call 911.
- Keep people and pets away from the nest and its flight path.
- Do not block the entrance of a nest in a wall or soffit — the insects can chew through into the house.
- Do not use gasoline or fire, and do not knock a nest down with a hose or stick.
- For nests in walls, in the ground, high up, or larger than a fist, call a licensed pest control company.
What usually causes it
- Sheltered spots under eaves, deck rails, shutters and play sets
- Gaps in siding, soffits and vents that give access to wall and attic voids
- Old rodent burrows and landscape timbers used by ground-nesting yellowjackets
- Open trash, fallen fruit and sweet drinks that attract foraging wasps
What a professional will do
A pest control technician identifies the species, treats the nest with a labeled product, usually at dusk or dawn when the colony is inside, and removes accessible nests. For nests inside walls they treat through the entry point and advise when it is safe to seal it.
How to prevent it
- Check eaves, sheds and play equipment in spring, when nests are small
- Seal gaps in siding, soffits and around utility lines
- Keep trash cans covered and pick up fallen fruit
- Leave honey bees alone and call a beekeeper — they are not wasps
Rules and paperwork in Pennsylvania
- Businesses that apply pesticides for hire in Pennsylvania must hold a Pesticide Application Business License, and their applicators must be certified, through the Department of Agriculture.
Sources: Pennsylvania Department of Agriculture — pesticide programs. Rules change — confirm current requirements with the agency and with your municipality.
Frequently asked questions
Will the nest be reused next year?
Wasp and hornet colonies die off in winter and old nests are generally not reused, but a sheltered spot that suited them once often attracts new queens.
Are exterminators licensed in Pennsylvania?
Yes. Businesses that apply pesticides for hire must be licensed by the Department of Agriculture and their applicators certified.
How can I tell wasps from honey bees?
Honey bees are fuzzy and golden-brown and form clusters or live in cavities with wax comb. Wasps and hornets are smooth and brightly marked, with paper nests.
Go deeper
Our full pest control guide covers how the work is done, what affects the price, and what to ask before you hire, and there is more on general pest control.
This guide is general information, not a substitute for a professional assessing your home. If you are unsure whether something is safe, treat it as if it is not.