Nest Under the Deck: How to Identify It and Have It Removed?

Contents

• Identifying a Nest Under Your Patio: Suitable Treatment Options

• Prices and Steps Involved in Removing a Wasp or Hornet Nest

• Where can you get fast and reliable service for your patio?

• Conclusion

You take your coffee out onto the wooden deck, and there you notice a flurry of activity. Insects are constantly going in and out of the same spot—between two deck boards, or through a small hole in the ground right next to the pool. This isn’t just a random stopover. It’s a colony that has found the perfect spot in your home: dry, dark, and sheltered from rain and predators.

Things to remember

• We go beyond a simple practical guide to offer expertise on identifying species (wasps vs. Asian hornets) that nest under deck boards

• The focus is on the technical challenges of access and the need for safe, professional service year-round, with full transparency regarding pricing and the steps involved in Frelons’ service process

• tailored treatment options

• Compare options and take action.

A nest under the deck, ...this is the most troublesome scenario we encounter. Not because the insects are more aggressive than elsewhere, but because the nest is invisible and inaccessible. You don’t know its size, the species, or exactly where it begins. And the day someone makes the floorboards shake by walking barefoot, the colony comes out. Quickly. In droves.

We respond to these kinds of situations year-round, even in the middle of winter, for nests of Asian hornet found in hedges or under structures. In this article, we’ll explain how to identify what’s living under your deck boards, what it really costs to get rid of it, and why using a can of insecticide from the hardware store is, in this specific case, a very bad idea.

Identifying a Nest Under Your Patio: Suitable Treatment Options

The first thing to do: observe it from a distance for two or three minutes. There’s no need to get within thirty centimeters. Identifying a wasp or hornet nest depends mainly on the activity and the way the insects look when they’re flying.

Visit common wasps and German wasps are the champions of hidden nests. They love cavities: under a wooden deck, in an embankment, under a concrete slab, in an old field mouse burrow. Small, bright yellow with black stripes, slender in build, and with a lively flight. You’ll see them constantly coming and going through a single opening, sometimes no wider than a two-euro coin. This, by the way, answers a question we’re often asked: in our region, nine times out of ten, the insect that builds a nest in the ground is a wasp. The nest itself is made of chewed wood pulp, gray in color, ball-shaped, and it grows throughout the season. By August, it can reach the size of a soccer ball, containing 3,000 to 5,000 individuals.

Visit Asian hornet under a deck, it's rarer but it does happen, especially with the first nests of spring. Easily recognizable: entirely black thorax, dark abdomen with a single orange ring, and especially yellow legs at the tips. It is larger than a wasp (2.5 to 3 cm) but smaller than the European hornet, which is very reddish-brown and yellow. The Asian hornet typically nests high up, but 20 to 30 % of the nests are found at ground level: under a garden shed, in a compost bin, or under a wooden structure. If you see these insects hovering in front of your beehive or a window, that’s a strong warning sign.

And then there are the false positives. The mason bees and solitary bees These are the little clay tubes, these «cocoons,» stuck to a wall or between floorboards. They’re harmless, don’t form colonies, and disappear on their own. You should never kill them. Neither should you kill bumblebees: they also nest in the ground, but their colony dies off naturally in the fall, and they sting only as a last resort. A reputable professional will tell you this over the phone rather than sell you an unnecessary service.

When it comes to insect control, we tailor our approach based on what we find. For a wasp under a wooden deck, the preferred method is to inject an insecticide powder directly into the entrance hole using a telescoping pole. The worker wasps carry it deep into the nest, and the colony dies out within a few hours. For an Asian hornet nest, the protocol is stricter: a certified full-body suit, an injection pole, and—most importantly—complete destruction to prevent future queens from flying away. In both cases, access is the key factor. Sometimes one or two slats must be removed; other times, access is gained from the side of the deck. It is this assessment that determines the method, not the other way around.

Prices and Steps Involved in Removing a Wasp or Hornet Nest

Let's talk numbers, because that's often the first question. In Belgium, the Fee for removing a nest The cost of wasp removal ranges from 90 to 130 euros, including tax. For a wasp nest under a deck, expect to pay between 110 and 160 euros: the surcharge covers the time spent locating the problem, the possible removal of a blade, and the difficulty of blind injection. A hornet's nest under a deck or a ground-level structure falls within the same range, with an additional charge if the nest is large or if access requires working on one’s knees in a confined space.

Three factors really drive the cost of destroying a nest : the height or depth of access, the species involved, and the urgency. A service call on a Sunday or at 9 p.m. isn’t charged at the same rate as one on a Tuesday morning. We make this clear over the phone—there are never any unpleasant surprises on the bill.

Good news about the Asian hornet: In several municipalities in Wallonia and Brussels, the cost of extermination is partially or fully covered as part of the regional effort to combat this invasive species. It’s worth asking us about this when you call—we’re familiar with the current programs and can guide you.

Visit steps of the procedure, specifically:

• The phone call or the form. Describe what you see. A photo or a short video taken from a distance is extremely helpful in identifying the species before you even have to go out there.

• The Pest Control Estimate. Announced verbally and confirmed in writing. Fixed price—no «starting at» prices that double once you get there.

• The Meeting. Generally within 24 to 48 hours; same-day service in cases of actual danger (known allergy, children, unavoidable situation).

• On-site survey. The technician locates the exact entry hole, checks to see if there are multiple holes, and determines whether disassembly is necessary.

• Treatment. Injection, securing the perimeter, waiting for the foragers to return and die in turn.

• Removal or plugging. If the nest is accessible, remove it. Otherwise, block off access to prevent it from being reoccupied and to keep pests—which are attracted to the dead larvae—from coming in.

• Follow-up. If traffic persists after 48 to 72 hours, we'll follow up again. Included in the price.

What about store-bought products? An aerosol can costs 12 euros and works very well on a small, visible nest hanging from a ledge, treated at dusk. Under a patio, it’s useless. The spray doesn’t reach far enough; you’ll kill the guards at the entrance, the colony will go on alert, and you’ll end up with fifty angry wasps between you and the door. That’s how most of the multiple stings we hear about happen. The same logic applies to a nest in an inaccessible roof: you need remote-injection equipment and full protective gear—not just a ladder and some courage.

Where can you get fast and reliable service for your patio?

We created Frelons.be for one simple reason: too many people have to wait for days with an active nest just three meters from their dinner table. The Safety on Your Deck should not depend on whether a firefighter is available or on the chance of dialing a number that someone answers.

Our teams cover Belgium and provide services all year round. This isn’t just a marketing gimmick. In January and February, we track down Asian hornet nests that have become visible in the bare trees: every nest destroyed out of season means potentially hundreds fewer queen hornets the following spring. In March and April, we remove primary nests—about the size of a golf ball—often tucked under an awning, in a garden shed, or right under a deck board. This is the ideal time: just one queen, no risk, and a quick job. From June through October, it’s peak wasp season, and that’s when we’re working at full capacity.

Each professional pest control technician Everyone in our network works with full protective gear (certified puncture-resistant coveralls, gloves, and a face shield), products approved in Belgium, and liability insurance. This last point is more important than you might think: if a blade from your wooden deck If it gets damaged during the treatment, or if a neighbor gets stung, it’s covered. But if a homeowner uses insecticide at home, it’s not.

Our emergency eradication service It is activated as a priority in three situations: if there is someone with allergies in the household, if a nest is located in a mandatory passageway (front door, staircase, pool access), or if young children are playing nearby. A wasp sting hurts; ten stings can land you in the hospital; and for someone with an allergy, even a single sting is enough to trigger an anaphylactic shock. This is no joke.

How can you reach us? Give us a call or fill out the form on our website. We’ll ask for your ZIP code, a description of the insect, the exact location, and, if possible, a photo. A Expert at Frelons.be We’ll call you back, identify the species, quote a price, and schedule a visit. If we determine that the nest poses no danger (bumblebees, solitary bees, or a nest that’s already dead at the end of the season), we’ll let you know and won’t come out. Trying to sell an unnecessary service doesn’t take long to become common knowledge in a country of eleven million people.

One last practical tip while you wait for us to arrive: cordon off the area. Place a chair across the entrance, put up a ribbon, and—most importantly—warn the children. No sweeping, no spraying water, no smoke. A peaceful colony remains manageable, but a disturbed colony can become dangerous for several hours.

Conclusion

A nest hidden under the deck boards is the scenario where improvising costs the most—both in stings and in money. Take three minutes to observe, take a photo from a distance, and leave the diagnosis to someone who sees this fifty times a week. Whether it’s a wasp, a European hornet, an Asian hornet, or just a mason bee—the answer isn’t the same, and neither is the treatment.

Contact Frelons.be for a clear quote and prompt service, whether it’s the summer season or the middle of winter. You’ll be able to enjoy your patio, your pool, and your outdoor meals again. That’s the whole point, after all, isn’t it?

Frequently asked questions