Can you have a wasp or hornet nest in your chimney?

Contents

• Prices and Estimates for Removing a Hornet's Nest from a Chimney

• Steps Involved and Service Options for Unclogging Your Drain

• Where to Get Fast and Safe Service with Frelons.be

• Conclusion

Yes. And it’s actually much more common than people realize. A chimney flue is warm, dry, dark, and sheltered from the wind and rain: for a hornet queen or a wasp colony looking for a place to settle in the spring, it’s a five-star spot. Most articles on the subject talk about birds—jackdaw nests in the chimney, crow nests in the chimney, and sometimes even an owl’s nest. All of that happens, of course. But a bird’s nest in your chimney flue will never sting you.

Things to remember

• Unlike traditional bird guides, we specifically address the danger posed by hymenoptera in ducts

• We highlight Frelons' expertise

• be for the safe removal of Asian hornet nests, which are active year-round, by combining fire safety and pest control

• Compare options and take action.

Hymenoptera are a different story. A constant buzzing behind the fireplace surround, insects coming and going around the chimney cap in July, wasps appearing in the living room without you knowing where they’re coming from—these are the signs that should set off alarm bells. And if you see large brown insects with yellow legs circling the roof, they’re likely Asian hornets, which are now found throughout Belgium and are active for much longer during the year than you might think.

The real problem is the combination of risks. A chimney blocked by a nest means restricted draft, and restricted draft in the winter means the danger of carbon monoxide in the house. Add to that a colony defending its territory just three meters from your window, and you’ll understand why you shouldn’t light a fire or climb onto the roof with an insecticide spray. We’ll explain what to do, how much it costs, and how we handle the situation.

Prices and Estimates for Removing a Hornet's Nest from a Chimney

The first question we’re asked on the phone, nine times out of ten, is: «How much will it cost me?» The honest answer: it depends on three things—height, access, and species. For a wasp nest in a chimney flue that’s accessible from the ground or through a chimney cleanout hatch, the cost is generally between €90 and €150. As soon as we have to climb onto a roof or use a ladder or telescopic pole, the cost of removing a nest from a chimney tends to rise to between €150 and €250. And for a hornet’s nest in the chimney of a three-story house, with a sloped roof and work at height requiring safety measures, expect to pay between €200 and €350.

These are rough estimates, not set-in-stone figures. That’s exactly why we give you a price before we come out, not after. A reliable pest control estimate can be done over the phone in just a few minutes: you describe the location, send a photo of the roof or vent via text, and we’ll give you the price. No «we’ll see when we get there,» no surprise surcharges once the truck is parked in front of your house.

A small but important detail in Belgium: the Asian hornet is an invasive alien species. Depending on your municipality or region, part of the cost may be covered, or at the very least, you’re encouraged to report sightings to official platforms. We’ll be upfront with you when that’s the case, because we’d rather have a nest removed than left in place due to budget constraints. Every untreated Asian hornet nest could potentially produce hundreds of queen hornets the following year.

Also be wary of prices that seem too good to be true. You’ll see ads offering services for €50 all-inclusive. At that price, there’s no liability insurance, no proper protective gear, and no approved pesticide. The cost of removing a hornet’s nest primarily reflects the risk involved: a full-body suit, working at heights, and the use of approved professional insecticides. A homeowner who tries to tackle the job themselves with a supermarket-bought spray can three meters off the ground often ends up in the emergency room.

One final note about the bill: don’t confuse pest control with chimney sweeping. Removing a nest does not mean the chimney has been swept. After we’re done, your chimney sweep will need to inspect the flue and remove any debris, especially if there was also an old bird’s nest in the chimney below. Two different trades, two separate jobs, but we often work closely with local chimney sweeps.

Steps Involved and Service Options for Unclogging Your Drain

Are you wondering what actually happens when we arrive at your home? Nothing spectacular, but every step serves a purpose.

• Identification. Common wasp, German wasp, European hornet, Asian hornet, honeybee: these require different treatments. If there’s a honeybee in a chimney, you don’t handle it the same way; you first seek a solution with a beekeeper if the hive can be salvaged. An Asian giant hornet in a chimney flue, on the other hand, must always be exterminated.

• Locating the nest. A nest in a chimney can be at the top of the flue, halfway up on a soot deposit, or behind the elbow above the firebox. By observing the workers’ path for a few minutes, you can pinpoint the actual entrance. An inspection camera is sometimes used when the flue is long.

• Security. Close the windows, move occupants and animals away, set up the ladder or aerial platform, and wear full protective gear. Never work on a wet roof without a safety harness.

• Treatment. Application of a professional-grade insecticide (in powder or gel form) directly into the nest using a telescopic pole. Worker bees returning to the nest in the following hours spread the treatment to the rest of the colony. Full effect within a few hours.

• Withdrawal and inspection. Whenever possible, we physically remove the nest and debris to clear the passageway. A chimney blocked by a nest remains dangerous even after the insects have died: the cardboard in the nest burns very easily, and a hornet’s nest in a chimney can cause a chimney fire.

We provide this pest control service year-round. This is something I want to emphasize, because many people think that hornets «disappear» in October. Asian hornet colonies remain active until November—sometimes December during mild fall seasons—and the queen hornets overwinter in sheltered nooks and crannies: attics, under roofs, and abandoned ducts. By February and March, we’re already treating primary nests the size of a tennis ball. Treating them at this stage is ten times easier and half the cost.

A word about what not to do, because we often end up cleaning up the mess. Don’t light a fire to smoke out a nest: the smoke makes the hornets furious before killing them, and they’ll come out through the fireplace grate—and into your home. Don’t block the top of the vent: the insects will look for another way out, and that other way out is your living room. Don’t spray water from the garden with a hose. And above all, don’t climb onto the roof without protection: about ten Asian hornet stings are enough to cause a serious reaction, and just one is enough if you’re allergic.

We also offer to install anti-intrusion mesh on the chimney cap after the service. Made of fine-mesh stainless steel, it keeps out both hymenoptera and birds—including that infamous jackdaw nest in the chimney that returns to the same spot every spring. It takes just thirty minutes, and you won’t have to worry about it for ten years.

Where to Get Fast and Safe Service with Frelons.be

A nest discovered on a Friday evening isn’t going to wait until Monday morning. That’s why we operate with short turnaround times: most of our Asian hornet removal services are carried out within 24 to 48 hours of the call, and on the same day in cases of genuine emergency (young children, someone in the household with allergies, or a blocked chimney in the middle of winter with a wood-burning stove).

Frelons.be serves all of Belgium with teams assigned to specific areas. When you call, you’ll speak with someone who knows the area—not a call center agent. You’ll be asked specific questions: what the insect looks like, how many are around the roof, how high up they are, and whether the chimney is still in use. Within three minutes, we’ll know if it’s a wasp, a European hornet, or an Asian hornet, and we’ll give you a time slot and a price.

Our technicians are experts in nest removal, trained to work at heights and equipped with poles reaching up to 20 meters. In practice, we can treat a nest at the top of a vent without necessarily having to climb onto the roof, which reduces both risk and cost. Professional liability insurance, approved products, and traceability of the service: everything you need to ensure you’re covered if anything goes wrong.

What really sets us apart is our availability outside the peak season. Many pest control companies treat wasp infestations from June through September and then move on to other things. We focus on the Asian hornet year-round, because the battle against this species is won precisely during the periods everyone overlooks: when the queen hornets emerge from hibernation in February–March, and the late nests in November that release future queens. A nest destroyed in March means several thousand fewer hornets in your neighborhood the following summer.

The easiest way to contact us is by phone or through the form on our website, with a photo attached. A photo of the chimney cap or the insect—even if it’s blurry—saves us a tremendous amount of time. We’ll get back to you with a fixed price, and we won’t change that price once we’re on-site. If your municipality helps cover the cost of removing Asian hornet nests, we’ll let you know and handle the paperwork.

And if it turns out not to be a hornet but a bird’s nest in the chimney flue, we’ll let you know that too—without charging you for an unnecessary service call. In that case, you’ll need to contact a certified chimney sweep, taking care to respect the protected nesting periods. Everyone has their own area of expertise.

Conclusion

A nest in the chimney is never a trivial matter, but a wasp or hornet nest in the chimney poses two dangers at once: stings and a blocked flue, with the resulting risk of carbon monoxide poisoning and a chimney fire. The first step is simple: don’t light a fire, don’t block the flue, and don’t climb onto the roof. Call us.

Do you hear a buzzing sound in your duct or see insects swarming around your roof? Take a photo, pick up your phone, and contact Frelons.be. Get an instant quote, fast service, and a team that deals with Asian hornets year-round—not just when the weather is nice.

Frequently asked questions