Cockroaches coming from the neighbours: what to do first
When cockroaches come from your neighbours, you need to act on two fronts at once: block what attracts them to your home and treat the source, not just the visible individuals. Otherwise, they'll return through the same entry points, especially in apartment buildings, kitchens, and damp areas.
The classic approach is to spray as soon as you see one. It feels like you're taking action, but you're often only catching the cockroaches that are just passing through. If the colony is in a neighbour's house, in a utility duct, a hollow wall, or a common room, you need a method that reaches the nest.
When the problem becomes repetitive, you may want to consider a targeted treatment such as Acose Trap (c) cockroach gel , especially if you have already understood that the entry point is not the real heart of the problem.
Why do cockroaches move from one dwelling to another?
Cockroaches don't just randomly infest your home. They follow food, moisture, warmth, and discreet entry points. In an apartment building, they move easily between apartments, behind skirting boards, around pipes, under the sink, or near heating appliances.
This scenario is common when a neighbour already has an infestation, even a minor one. You can have a clean kitchen and still see cockroaches appear, because they don't necessarily seek out visible dirt: they look for shelter and easy access to water or food.
To better understand the most likely hiding places in your home, you can also read where cockroaches hide: a guide to spotting them in your home .
Signs that show the problem is coming from elsewhere
Neighbours are often suspected when cockroaches appear mainly at night, near shared walls, around pipes, or in the kitchen, even though there aren't many hiding places in your own home. Another clue: you see them after a change of season, renovations, or work being done in the building.
The first useful step is to observe where they emerge. If they always come from the same point, it's not a coincidence. It's then necessary to distinguish between a one-off intrusion and an established infestation. This difference is what determines the strategy.
If you're unsure whether to call them cockroaches or roaches, the details can be important when identifying the species and its behaviour. A helpful reminder here: cockroaches and roaches: what's the difference ?
What needs to be done right away
Limit what attracts them
Clean up crumbs, grease, and damp areas. Empty trash cans regularly, wipe down the sink at night, and store food in sealed containers. Even if the cockroaches come from elsewhere, your home shouldn't provide them with a welcoming place to arrive.
Close the accessible passages
Look for openings around pipes, skirting boards, cable passages, and vents. A cockroach can squeeze through even the most discreet spaces. The goal isn't to seal everything off, but to minimize the most obvious entry points. In an apartment, this step is very helpful when the infestation is still moderate.
Monitor risk areas
Look under the sink, behind the fridge, near the dishwasher, around worn seals, and in the base cabinets. If you see them mainly in these areas, it confirms that they are using the kitchen service areas as access routes.
Why a spray doesn't address the root of the problem
A spray might kill a single visible cockroach, but it won't destroy the colony that remains hidden. This is where many people waste time: they get immediate relief, then the cockroaches return. When they come from neighbours, the real challenge is breaking the cycle, not just eliminating the ones that pass through your home.
In practice, the most frustrating situations are those where you clean a lot, see few cockroaches during the day, and then they reappear at night. This often means the source is larger than just your kitchen. In this case, bait works better because it can be taken back to the nest.
When to use a bait gel
A bait gel becomes relevant when you've identified regular activity, visible cockroaches in the kitchen or near damp areas, and you want to target the colony rather than individual insects. The advantage lies in the domino effect: a contaminated cockroach carries the product back to the nest and contaminates the colony.
With Acose Trap (c), the principle is simple: discreet, odourless installation, with initial results in two days and colony elimination in ten days. For a problem originating from neighbours, this type of treatment makes sense because it acts where cockroaches congregate, not just where they pass.
The product is available here: Acose Trap cockroach gel (c) .
Concrete examples: how to proceed depending on the situation
In an apartment
Start with the kitchen and bathroom. These are the areas most often connected to neighbours by pipes and ducts. If cockroaches appear near a shared wall, treat the visible entry points and monitor for their return for several days.
In a condominium
The problem isn't always visible from one apartment to another. It can spread through the building's systems. If several apartments are affected, coordinating actions is extremely helpful. Otherwise, everyone deals with it on their own without addressing the common source.
In a restaurant or bakery
When the activity attracts heat, humidity, and food products, the stakes are even higher. Shelters must be reduced, technical areas cleaned, and odour-free treatments applied to avoid disrupting service. Feedback from the field shows that inaction quickly becomes more costly than a properly applied treatment.
Common mistakes to avoid
- Limit yourself to killing visible cockroaches without targeting the nest.
- Clean up and then leave a source of moisture or food accessible.
- Forget about going behind furniture and around pipes.
- Multiplying products without following a clear order.
- Waiting for the neighbour to act without protecting one's own home.
How do you know if you're going in the right direction?
You're on the right track if you see fewer crossings near the kitchen, less nighttime activity, and a gradual decrease in appearances. When the treatment is well-targeted, the first changes are noticeable quickly, and then the pressure decreases over the following days.
If, on the other hand, the cockroaches keep returning to the same spot, the point of entry, the damp areas, and the treatment strategy need to be reviewed. This isn't necessarily a failure; it's often a sign that they're still moving between two areas.
To take a more comprehensive approach, you can consult our main guide on how to get rid of cockroaches permanently .
FAQ
Can cockroaches only come from the neighbours?
Yes, especially in apartment buildings. They can travel through ducts, cavity walls, pipes, or skirting boards. Even if your apartment is clean, an infested neighbour can be enough to bring cockroaches into your home. That's why you need to treat entry points and not just clean more.
Should you talk to your neighbour if the cockroaches are coming from their house?
Yes, if the situation allows. Doing it calmly can help coordinate actions and prevent the problem from escalating from one household to another. But in the meantime, protect your own space. You don't want to wait for someone else to act before you start.
Is a gel sufficient if the cockroaches are coming from the neighbours?
Gel is often more effective than spray in this case because it targets the colony. However, it must be placed in the right locations and in an environment that doesn't offer them too much competing food. Otherwise, the effect is less pronounced and slower.
How long does it take to see a decrease?
With well-placed bait, initial results can appear within two days. The colony can be eliminated in ten days if the source is properly treated and access points are monitored. If the cockroaches return, access points and hiding places should be checked.
Frequently Asked Questions
Can cockroaches only come from the neighbours?
Yes, especially in apartment buildings. They can travel through ducts, cavity walls, pipes, or skirting boards. Even if your apartment is clean, an infested neighbour can be enough to bring cockroaches into your home. That's why you need to treat entry points and not just clean more.
Should you talk to your neighbour if the cockroaches are coming from their house?
Yes, if the situation allows. Doing it calmly can help coordinate actions and prevent the problem from escalating from one household to another. But in the meantime, protect your own space. You don't want to wait for someone else to act before you start.
Is a gel sufficient if the cockroaches are coming from the neighbours?
Gel is often more effective than spray in this case because it targets the colony. However, it must be placed in the right locations and in an environment that doesn't offer them too much competing food. Otherwise, the effect is less pronounced and slower.
How long does it take to see a decrease?
With well-placed bait, initial results can appear within two days. The colony can be eliminated in ten days if the source is properly treated and access points are monitored. If the cockroaches return, access points and hiding places should be checked.
