Can bedbugs get in through windows?

Contents

• Bedbug migration from outside: understanding the risk in summer

• Solutions and prices to protect your windows against bedbugs

• Punaisesdelitbruxelles intervention packages: your instant quote

• Conclusion

I'm often asked on the phone, «My neighbor has bedbugs, can they get into my house through the window?» The short answer is yes. The long answer is that the phenomenon is more common than you might think, especially in Brussels apartment blocks in summer, when everyone sleeps with their windows open.

Things to remember

• We lift the veil on a little-known risk: the migration of bed bugs between neighbouring apartments via open windows and façades in summer.

• The article combines technical expertise on insect behavior and concrete solutions (physical barriers and professional treatments) with transparent pricing for Brussels residents.

• Understanding summer risk

• Compare options and take action.

Bed bugs in a neighboring apartment are a real source of anxiety. And rightly so. These bugs don't fly, they don't jump, but they do crawl. They crawl along walls, gutters and window frames. At night, attracted by the CO2 you breathe out as you sleep, they are capable of traveling several meters to find a host. When your bedroom is just a few dozen centimetres from your neighbor's, the math is easy.

I've written this article for tenants and landlords in Brussels who want to understand this risk and, above all, how to protect themselves against it. With solutions that work, clear prices and a proven protocol.

Bedbug migration from outside: understanding the risk in summer

First, a figure: between June and September, our operations in Brussels increased by 40 %. This is no coincidence. Summer combines all the right factors for transmission from one apartment to another. Windows are left open at night to keep cool, high temperatures speed up the bedbugs' reproduction cycle (a female lays up to 5 eggs a day), and the insects are simply more active when it's hot.

So how does it work in practice? Bed bugs are lucifuges: they hate light and move around in the dark. At night, when a colony becomes too dense in a dwelling, certain individuals migrate. They follow vertical surfaces: exterior walls, façade joints, window frames. Window frames are a highway for them. Cracks in plaster, damaged silicone joints, the slightest gap is enough for them. We're talking about an adult insect that measures 5 to 7 mm and can flatten out to fit through a one-millimeter gap.

Where do bedbugs hide during the day? Wherever it's dark and cramped. Behind baseboards, in mattress seams, under peeling wallpaper. But also in roller shutter casings, window frames, cracks between frame and wall. It's precisely through these areas that they enter from the outside. A half-open window with a blind down is an invitation.

Be careful not to confuse the species. In summer, you may also see insects in windows that are not bedbugs. The diabolical bug (Halyomorpha halys), for example, is a grayish-brown flying insect that seeks out the warmth of dwellings in autumn. It smells bad when crushed, but doesn't bite humans. Visit bat bugs, These are very similar to conventional bedbugs, and can also enter through windows, especially if bats are nesting under your roof. If you find insects near your windows in summer, the first step is to correctly identify the species before panicking.

The real bed bug (Cimex lectularius) can be recognized by its oval, flattened shape, its reddish-brown color (darker after a blood meal), and above all by its traces: small black spots on the sheets (droppings), traces of blood, translucent molts. If you see these signs near your windows or on your bedding, there's no room for doubt.

The typical scenario in Brussels: a tenement building in Ixelles or Saint-Gilles, old apartments with cracked facades. A tenant is infested, doesn't treat (or is slow to do so), and within a few weeks, bedbugs colonize the adjacent apartments. Through stairwells, service shafts and, yes, windows. Transmission between neighboring apartments is no urban legend. It's a fact of life.

Solutions and prices to protect your windows against bedbugs

First thing to do if you suspect a risk from the neighborhood: create a physical barrier. Not in three weeks. Now.

Visit mosquito net against bed bugs is the simplest and most underrated solution. But not just any mosquito net. Standard mosquito nets are too large. To block a bedbug, you need a mesh size of less than 1 mm. Mosquito nets with fine mesh (0.5 mm or less) are available in DIY stores and online. Expect to pay between €15 and €40 per window for a fixed-frame model, and between €50 and €80 for a made-to-measure roll-up model.

Installation must be impeccable. No gaps between frame and wall, no gaps at the bottom. Bedbugs will exploit the slightest defect. If you're a do-it-yourselfer, an aluminum frame with a thin mosquito net attached by magnetic clips will do the job just fine. Otherwise, a carpenter or our team can do the job for you.

Beyond the screen, you need to seal. Inspect each window frame for worn silicone seals, cracks in the plaster, gaps between the frame and the masonry. Use acrylic putty or silicone to fill these gaps. It's basic, but highly effective as an anti-insect barrier. One hour's work, a few euros' worth of materials, and you'll eliminate 80 % entry points.

Do window repellents work? Let's be honest: commercial repellent sprays (based on essential oils of lavender, tea tree, etc.) have a very limited effect on bedbugs. They are not sensitive to odors in the same way as mosquitoes. Some permethrin-based products applied to frames can have a temporary barrier effect, but this is a dressing, not a treatment. If your neighbor has a colony, a window repellent won't do the trick.

What really works is the combination of a physical barrier (fine screen + clogging) combined with a professional insecticide treatment preventive or curative. A technician applies a residual insecticide to areas of passage: window frames, baseboards, electrical outlets, bedheads. This product remains active for several weeks, killing bedbugs that pass through it.

The price of bed bug treatment in Brussels varies according to surface area and level of infestation. For a studio or T1, you should expect to pay between €150 and €250 per treatment. A T2 or T3, between €250 and €400. Most serious protocols require two passages 15 days apart to break the reproduction cycle (eggs are resistant to the first treatment). Don't be fooled by low prices: an all-inclusive treatment costing €80 often involves a single pass with a product that's not very effective. And you'll have to call back in a month.

To get rid of bedbugs around windows specifically, the four steps are: identify the species, seal the access points, fit a suitable mosquito net, and have the problem treated by a professional if the infestation is confirmed or if the risk comes from the neighborhood. In this order.

Punaisesdelitbruxelles intervention packages: your instant quote

At Punaisesdelitbruxelles, we've structured our offers so that you know exactly what you're paying for before we walk through your door. No surprises, no «ah but that's extra».

Here are our current packages for a exterminator in Brussels specialized bed bugs :

• Diagnosis + visual inspection 50 (deducted if you are taking medication). We inspect bedding, furniture, window frames and baseboards. We identify the species and level of infestation. You leave with a clear report.

• Studio / T1 package (up to 40 m²) 199 € per pass, two passes included in the standard protocol at 349 €. Professional targeted insecticide treatment, approved products, 6-week residual.

• T2 / T3 package (40 to 80 m²) 279 per pass, complete two-pass protocol at €499.

• Large units (80 m² and over) On request: customized quotation after inspection.

Each package includes treatment of critical areas: bedding, skirting boards, sockets, and of course window frames and shutter boxes. We don't treat by halves.

The question we are systematically asked: «What if it comes back?» Our result guarantee covers a free third pass if bedbugs are still detected within 30 days of the second treatment. That's our commitment. We won't let you down between bills.

To obtain a disinsectisation quote, it's fast. Call us or fill in the form on our website. We'll get back to you within 2 hours during the day. We'll ask you a few questions (surface area, type of home, signs observed, neighborhood concerned), and send you a detailed estimate by email. No commitment, no hidden costs.

One point that's very important to us is coordination with your neighbors. If your neighbor is infested and you treat only your home, the bedbugs will come back. It's a mechanical process. We offer coordinated interventions for several dwellings in the same building, with sliding-scale rates. We can also write a technical letter to the building manager or landlord to help break the deadlock. Because the biggest obstacle is often not the budget: it's the neighbor who refuses to treat.

Our technicians work in all the communes of Brussels-Capital: Ixelles, Saint-Gilles, Schaerbeek, Anderlecht, Forest, Molenbeek, Etterbeek, Uccle and others. Average time between your call and the intervention: 48 to 72 hours. In emergencies (massive infestation, presence of small children), we do our utmost to call the next day.

We use only professional products approved in Belgium, applied by certified technicians. No homemade recipes, no gadgets. A rigorous protocol, products that work, and follow-up until complete resolution.

Conclusion

Yes, bed bugs can get into your windows. It's a real risk, particularly in summer, and especially in Brussels buildings where apartments are close to each other. The good news is that this risk is manageable: fine-mesh screens, crack sealing and professional treatment if necessary.

If you have the slightest doubt, don't leave it lying around. If you spot a bedbug early, treatment is quick and easy. A colony that's been there for three months is a different story. Contact Punaisesdelitbruxelles for a diagnosis or a quote: we'll tell you what's going on, without jargon or pressure.

Frequently asked questions