Wasp nest in a bird box — what to do?
By Wespenprofis.ch · Reviewed by:Fachbewilligung Schädlingsbekämpfung VFB-S · Updated: 3 July 2026
At a glance
Wasps readily take over empty bird boxes, which offer them a ready-made, sheltered cavity. Do not open the box to check inside and do not take it down; keep your distance from the area and have the nest assessed by a professional.
Why this situation is tricky
An empty bird box or an unused bird house is an ideal nesting site for a young wasp queen in spring: dry, dark, protected from the weather and fitted with a small entrance hole that is easy to defend. Often the box is only noticed once wasps are already flying in and out in numbers — or when the annual autumn clean-out of the bird box is due and an active colony turns up inside. Because the box usually hangs on a tree, a house wall or a fence at head or arm’s height, the distance to people and pets is often short. In late summer, when the colony reaches its maximum size, even a slight knock at the mounting point can be enough to startle the insects.
What you should do straight away
- Do not open the bird box or take it down to check inside.
- Keep well clear of the area around the box.
- Do not seal or spray the entrance hole.
- Keep children and pets away from the mounting point.
- Call in a professional (/wespennest-entfernen) to remove the nest safely.
Good to know
Bird boxes are usually small, which is why even smaller nests under 5 cm can often be vacuumed out with little risk once they have been professionally assessed; for nests at a more advanced stage, cold treatment is used. After removal, the old nest is never colonised again — once cleaned, the box can be occupied by birds again the following spring. If the nest is in a garden shed or outbuilding instead, it is worth reading our guide Wespennest Gartenhaus. For general advice on what to do when you find a nest, see Wespennest gefunden — was tun.
Frequently asked questions
Why do wasps move into a bird box?
An empty, dry and dark box with a small entrance hole meets exactly the same requirements for a queen in spring as a natural cavity — it is sheltered and weatherproof.
Can I simply take the bird box down and carry it away?
No, we advise against it. The colony reads the vibrations caused by taking the box down as an attack and responds immediately by defending the nest. Leave this to a professional.
Can I use the bird box for birds again next year?
Yes. An old nest used by wasps is never colonised again. Once the nest has been removed professionally and the box has been cleaned, it is available to birds again the following year.