{"id":25095141,"date":"2026-08-24T10:19:20","date_gmt":"2026-08-24T08:19:20","guid":{"rendered":"https:\/\/frelons.be\/2026\/08\/24\/nid-de-guepes-ou-frelons-dans-une-cloison-signes-et-solutions\/"},"modified":"2026-08-24T10:19:20","modified_gmt":"2026-08-24T08:19:20","slug":"wasp-or-hornet-nest-in-a-wall-signs-and-solutions","status":"publish","type":"post","link":"https:\/\/frelons.be\/en\/2026\/08\/24\/nid-de-guepes-ou-frelons-dans-une-cloison-signes-et-solutions\/","title":{"rendered":"Wasp or Hornet Nests in a Wall: Signs and Solutions"},"content":{"rendered":"<h1>Wasp or Hornet Nest in a Wall: The Complete Guide<\/h1>\n<h3 id=\"sommaire\">Contents<\/h3>\n<ul>\n<li>\n<p><a target=\"_blank\" rel=\"noopener noreferrer nofollow\" class=\"text-primary underline toc-link\" href=\"#detecter-et-identifier-la-presence-d-un-nid-derriere-vos-cloisons\">Detect and identify the presence of a nest behind your walls<\/a><\/p>\n<\/li>\n<li>\n<p><a target=\"_blank\" rel=\"noopener noreferrer nofollow\" class=\"text-primary underline toc-link\" href=\"#pourquoi-les-guepes-et-frelons-s-installent-dans-le-placo-et-les-risques\">Why Wasps and Hornets Nest in Drywall, and the Risks Involved<\/a><\/p>\n<\/li>\n<li>\n<p><a target=\"_blank\" rel=\"noopener noreferrer nofollow\" class=\"text-primary underline toc-link\" href=\"#traiter-un-nid-loge-dans-une-cloison-solutions-et-securite\">Dealing with a Nest in a Partition Wall: Solutions and Safety<\/a><\/p>\n<\/li>\n<li>\n<p><a target=\"_blank\" rel=\"noopener noreferrer nofollow\" class=\"text-primary underline toc-link\" href=\"#conclusion\">Conclusion<\/a><\/p>\n<\/li>\n<\/ul>\n<p>A steady scratching sound behind the drywall in the bedroom, around 10 p.m. Then a low hum, like a refrigerator running rough. The next morning, two wasps are flying around the room even though the windows have been closed since the day before. We hear this story several times a week between May and October.<\/p>\n<h3 id=\"ce-qu-il-faut-retenir\">Things to remember<\/h3>\n<ul>\n<li>\n<p>We confirm the technical feasibility of an infestation in drywall by explaining in detail how these insects use moisture to burrow through the walls<\/p>\n<\/li>\n<li>\n<p>The article stands out by offering a reassuring protocol for identifying hornets by sound and appearance, while highlighting the expertise of Frelons.be, which is available year-round.<\/p>\n<\/li>\n<li>\n<p>Detect and identify the presence of a nest behind your walls<\/p>\n<\/li>\n<\/ul>\n<p>And the first question that comes to mind\u2014always the same one\u2014is: Is it really possible for a nest to be <em>in<\/em> The wall? Yes. Completely. A drywall partition is a hollow, dry, thermally insulated space, with electrical conduits running through it that serve as access tunnels. For a queen looking for a place to establish her colony in the spring, it\u2019s better than an attic.<\/p>\n<p>The good news: Most of the time, you can locate a nest in a wall without having to tear it down. But you still need to know how to listen, look in the right place, and\u2014most importantly\u2014avoid making the classic mistake of the weekend DIYer (we\u2019ll come back to this below; it sends people to the emergency room every summer). At Frelons.be, we provide service year-round, including in the winter, for Asian hornet nests found in buildings.<\/p>\n<h2 id=\"detecter-et-identifier-la-presence-d-un-nid-derriere-vos-cloisons\">Detect and identify the presence of a nest behind your walls<\/h2>\n<p>Let's start with sound, because it's almost always the first sign. A <strong>scratching sound<\/strong> in the wall\u2014a light, irregular sound, a bit like someone rubbing sandpaper very gently. It\u2019s the mandibles of the worker wasps scraping the surface to make the paper pulp for their nest. Many people think of mice at first. The difference is clear: rodents make noise mainly at night, with scurrying and sharp little taps, whereas wasps work during the day and stop almost entirely after sunset.<\/p>\n<p>The second clue is the <strong>buzzing in the wall<\/strong>. Press your ear against the panel, or better yet, place an upside-down wine glass against the wall and listen through the stem of the glass. You\u2019ll hear either nothing or a continuous humming sound, which is louder on hot afternoons. A mature common wasp nest in August can contain 3,000 to 5,000 wasps. At this stage, the noise can sometimes be heard from the middle of the room.<\/p>\n<p>Next, go outside. The nest is inside, but the entrance is almost always outside. Look for a <strong>outlet hole<\/strong> : a crack in the plaster, a loose window seal, a ventilation hole in a roller-shutter box, a poorly sealed air conditioning duct, the space under a roof overhang. Stand five meters away, remain still, and watch for ten minutes. If a nest is active, you\u2019ll see constant coming and going\u2014often one entry every two or three seconds during peak season. This activity is the most reliable sign there is. Note the exact location and take a photo\u2014it\u2019ll save the technician a lot of time.<\/p>\n<p>Inside, keep an eye out for the <strong>insects in the wall<\/strong> that end up going the wrong way. If you see a few workers regularly appearing in the same room, always near an outlet, a recessed light, or a baseboard, that means they\u2019re coming out from inside. Also check the <strong>moisture stains on the drywall<\/strong> : A brownish or yellowish ring that grows slowly may indicate a large nest that is softening the plaque through condensation. In extreme cases, the plaque becomes so brittle that a finger can pierce it.<\/p>\n<p>That leaves the question of the species. Common wasp: bright yellow and black stripes, small, aggressive when approached near the entrance. European hornet: two to three times larger, reddish-brown, with a very distinctive low-pitched buzz, often attracted to light in the evening. Asian hornet: black thorax, yellow legs at the tips, a single orange stripe on the abdomen. The <strong>drones in a partition<\/strong> They also exist and are easy to distinguish: large, hairy, slow-flying, with colonies ranging from 50 to a maximum of 200 individuals, and much less dangerous. They disappear on their own by the end of summer. If you\u2019re unsure, send us a photo\u2014we can identify them in a few minutes.<\/p>\n<h2 id=\"pourquoi-les-guepes-et-frelons-s-installent-dans-le-placo-et-les-risques\">Why Wasps and Hornets Nest in Drywall, and the Risks Involved<\/h2>\n<p>A queen that emerges from hibernation in April is looking for three things: a dry shelter, a stable temperature, and a discreet entrance. A partition wall checks all three boxes better than any tree. Between the drywall and the load-bearing wall, there\u2019s often a 5- to 10-cm gap\u2014sometimes even more in stud-framed wall linings. The insulation keeps the heat in, the ducts create tunnels, and no one ever goes poking around in there. For the colony, it\u2019s the penthouse.<\/p>\n<p><img decoding=\"async\" class=\"max-w-full h-auto rounded-md\" src=\"https:\/\/nghaeknymynesecnqcmd.supabase.co\/storage\/v1\/object\/public\/article-images\/article-1787227663979-nid-de-guepes-ou-frelons-dans-une-cloison-signes-et-solutions.png\" alt=\"Wasp or Hornet Nests in a Wall: Signs and Solutions\"><\/p>\n<p><strong>Do wasps eat drywall?<\/strong> They don't digest it, but they do gnaw on it, yes. Plain plaster isn't their favorite material (they prefer dead wood and cardboard), except when it's damp. And that's where it gets interesting: <strong>moisture in the plaster<\/strong> It softens the panel and turns the facade board into a paste that\u2019s easy to chew through. An old roof leak, capillary action, a thermal bridge that constantly causes condensation\u2014and the nest literally grows as it burrows its way through. Residents have filmed holes the size of a hand that appeared in a bedroom within a few weeks. This isn\u2019t an urban legend\u2014it really happens.<\/p>\n<p>Visit <strong>property damage<\/strong> don\u2019t stop at the hole. A wasp nest becomes heavy by the end of the season, and it generates a lot of moisture from the respiration of thousands of wasps. The result: swollen drywall, blistered paint, mold behind the insulation, and a persistent sweetish odor. European hornets go even further\u2014they gnaw away at the wood in the framing and rafters. And when the colony dies off in November, the abandoned nest becomes a feeding ground for moths, dermestid beetles, and various larvae. A nest that isn\u2019t removed is a problem that turns into yet another problem.<\/p>\n<p>The real risk, though, is the sting. A nest in a wall is, by definition, close to the occupants\u2014sometimes as close as 40 cm from the head of the bed. Wasps defend their entrance within a radius of 2 to 3 meters, while Asian hornets defend theirs within 5 meters or more. Drilling a hole in a wall, driving in a screw, or putting up a shelf in the wrong place: any of these actions can trigger an immediate attack. Every year in Belgium, emergency responses are required for people who have been stung ten or fifteen times in a matter of seconds in their own homes.<\/p>\n<p>Visit <strong>Asian hornet<\/strong> deserves a special mention. We associate it with ball-shaped nests in tall trees, but its primary spring nests are often built in sheltered spots: shutter boxes, garden sheds, garages, and sometimes <strong>partitions<\/strong> accessible through a service opening. A <strong>Asian hornet nest in a wall cavity<\/strong> It remains rare, but we treat cases every season. It must always be destroyed: a mature colony releases several hundred future queens that will go on to establish new colonies elsewhere the following year, not to mention the pressure it puts on nearby apiaries. Contrary to what is sometimes reported, you should not leave an Asian hornet nest alone until winter.<\/p>\n<h2 id=\"traiter-un-nid-loge-dans-une-cloison-solutions-et-securite\">Dealing with a Nest in a Partition Wall: Solutions and Safety<\/h2>\n<p>First things first, and let\u2019s be blunt: don\u2019t break through the wall. Never. This is the most costly mistake every summer. Breaking through the drywall to \u00abtake a look\u00bb creates an opening into your home and releases thousands of angry insects into a closed room. The second classic mistake: sealing the exit hole with silicone or expanding foam. The wasps don\u2019t die; they look for another way out, and that other way out is almost always inside the home, through an electrical outlet or a recessed light fixture. We\u2019ve seen families evacuate their homes because of this.<\/p>\n<p>Commercial aerosol sprays? They\u2019re effective on a visible, exposed nest that\u2019s sprayed from close range. On a <strong>niche nest<\/strong>, the product only affects the few workers near the entrance. The center of the nest, the queen, and the brood remain intact, and the colony recovers within a week, often becoming more aggressive. You\u2019ll have spent just 15 euros and ended up with an angry swarm.<\/p>\n<p>How do you <strong>Find a wasp nest without destroying it<\/strong> The wall? We use a combination of three methods. Observing the workers\u2019 path from the outside pinpoints the entry point to within a few centimeters. The thermal camera detects the warm area: an active colony maintains an internal temperature of about 30 \u00b0C, which stands out very clearly against a cold wall. And the endoscope\u2014a micro-camera on a flexible rod that we slide through an 8-mm hole (through a removed outlet, for example)\u2014visually confirms the nest\u2019s location and size. Three tools, zero demolition.<\/p>\n<p>The treatment itself is administered by injection. A professional-grade insecticide powder is introduced directly into the cavity, either through the perch or via a micro-drill hole. The worker bees carry it on their legs to the center of the nest, contaminating the queen and the brood. Activity drops within a few hours, and the colony dies within 24 to 48 hours. For a <strong>Removal of a hornet's nest<\/strong>, we work in certified full-body protective suits, often at the end of the day when all the worker bees have returned to the hive, which ensures that no forager bees come back to circle the building's facade afterward.<\/p>\n<p>Should you remove the nest afterward? For wasps, it\u2019s not necessary in most cases: the nest won\u2019t be reoccupied the following year and will break down on its own. Removal is recommended if the nest is large, or if there is already a <strong>moisture stain on the drywall<\/strong>, or if the wall is weakened. In that case, we carefully remove a section of the wall, dispose of it, sanitize the area, and then you can close it up (or we\u2019ll put you in touch with someone who can). For a nest of Asian hornets, removal is always required.<\/p>\n<p>While waiting for the work to begin: avoid the affected room, seal the bottom of the door with a towel, turn off any recessed lights near the area, and keep children and pets away. Don\u2019t tap on the wall to \u00absee if they react.\u00bb It works\u2014they\u2019ll react\u2014and you won\u2019t like what happens.<\/p>\n<p>Choose a <strong>pest control company<\/strong> For this type of project, it\u2019s not just about the product. It involves diagnostics, detection equipment, and a genuine guarantee of results. A <strong>Professional Pest Control<\/strong> A thorough ironing, free of charge, if business picks up again. The <strong>home security<\/strong> is just as important as elimination: we want the nest to die out and for nothing to come out into the living room.<\/p>\n<h2 id=\"conclusion\">Conclusion<\/h2>\n<p>A scratching sound in the wall, a humming noise behind the drywall, two wasps appearing out of nowhere: these are unmistakable signs that need to be addressed quickly. The larger the colony grows, the more difficult the treatment becomes, and the more severe the damage to the wall gets. A nest removed in June takes just twenty minutes to handle. The same nest in September means the wall has to be redone.<\/p>\n<p>Do you suspect a <strong>hornet in a wall<\/strong> or a <strong>wasp nest in the drywall<\/strong> At your home? Take a photo of the insect and the exit point, then call us. Frelons.be is available year-round, including weekends, and uses a thermal camera and endoscope to locate the nest without causing any damage. We\u2019ll tell you honestly whether it\u2019s an emergency or not, and we never break through a wall unless absolutely necessary.<\/p>\n<h2 id=\"questions-frequentes\">Frequently asked questions<\/h2>\n<details class=\"faq-item\">\n<summary>How can I tell if the noise in my wall is coming from wasps and not mice?<\/summary>\n<p>Wasps make a scratching sound during the day\u2014a light, irregular sound reminiscent of sandpaper being rubbed gently\u2014and their activity stops almost entirely after sunset. Rodents, on the other hand, are most active at night, with scurrying and sharp little taps. A continuous humming sound, louder in the afternoon when it\u2019s hot, confirms the presence of a colony.<\/p>\n<\/details>\n<details class=\"faq-item\">\n<summary>Is it possible to locate a nest inside a wall without breaking the drywall?<\/summary>\n<p>Yes, in most cases. Observing the comers and goers of the worker bees from the outside pinpoints the entry point to within a few centimeters, the thermal camera identifies the hot spot (an active colony is around 30 \u00b0C), and the endoscope inserted through an 8-mm hole\u2014such as a removed electrical outlet\u2014confirms the nest\u2019s location and size.<\/p>\n<\/details>\n<details class=\"faq-item\">\n<summary>Can wasps really damage drywall?<\/summary>\n<p>They don't digest drywall, but they gnaw on it when it's damp: the moisture softens the panel and turns the face paper into a paste that's easy to chew. With a roof leak or rising damp, holes the size of a hand can appear within a few weeks, accompanied by swollen drywall, blistered paint, and mold behind the insulation.<\/p>\n<\/details>\n<details class=\"faq-item\">\n<summary>Why is it especially important not to block the exit hole?<\/summary>\n<p>Sealing the opening with silicone or expanding foam does not kill the insects: they will look for another way out, and this is almost always inside the home, through an electrical outlet or a recessed light fixture. Families have had to evacuate their homes for this reason. Breaking through the wall yourself is just as risky: it releases thousands of insects into a closed room.<\/p>\n<\/details>\n<details class=\"faq-item\">\n<summary>Are over-the-counter insecticide sprays effective against a nest in a wall cavity?<\/summary>\n<p>No. These aerosols are effective only on a visible nest, sprayed at close range. Inside a wall, the product reaches only a few worker bees near the opening: the queen and the brood remain intact, and the colony recovers within a week, often becoming more aggressive. Professional treatment involves injecting a powder that the worker bees carry deep into the heart of the nest.<\/p>\n<\/details>\n<details class=\"faq-item\">\n<summary>Should we wait until winter if the nest belongs to an Asian hornet?<\/summary>\n<p>No, it must be destroyed, and the nest is always removed. A mature colony releases several hundred future queens that will go on to establish new colonies elsewhere the following year, not to mention the pressure this puts on neighboring apiaries. Frelons.be responds year-round, including in winter, to nests found in buildings.<\/p>\n<\/details>","protected":false},"excerpt":{"rendered":"<p>Wasp or Hornet Nests in a Wall: The Complete GuideTable of ContentsDetecting and Identifying a Nest Behind Your WallsWhy Wasps and Hornets Nest in Drywall and Ceiling\u2026<\/p>","protected":false},"author":2,"featured_media":25095140,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-25095141","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-non-classe"],"_links":{"self":[{"href":"https:\/\/frelons.be\/en\/wp-json\/wp\/v2\/posts\/25095141","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/frelons.be\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/frelons.be\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/frelons.be\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/frelons.be\/en\/wp-json\/wp\/v2\/comments?post=25095141"}],"version-history":[{"count":0,"href":"https:\/\/frelons.be\/en\/wp-json\/wp\/v2\/posts\/25095141\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/frelons.be\/en\/wp-json\/wp\/v2\/media\/25095140"}],"wp:attachment":[{"href":"https:\/\/frelons.be\/en\/wp-json\/wp\/v2\/media?parent=25095141"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/frelons.be\/en\/wp-json\/wp\/v2\/categories?post=25095141"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/frelons.be\/en\/wp-json\/wp\/v2\/tags?post=25095141"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}