Cockroaches are the pest people put up with longest. You see one at night, you kill it, and you tell yourself that was the only one. It never is.
Signs you have more than you think
- Seeing one in daylight. Cockroaches are nocturnal. Daytime sightings usually mean the harbourage is crowded.
- Droppings that look like ground black pepper in cupboard corners, drawer runners and behind the cooker.
- A musty, oily smell in the kitchen that does not go away with cleaning.
- Small brown egg cases glued into corners and cabinet joints.
- Smear marks along the edges of shelves and skirting.
Which cockroach is in your kitchen
Two matter in Nairobi. The German cockroach is small, light brown, with two dark stripes behind the head. It lives indoors, breeds fast and is the one in most kitchens. The American cockroach is much larger and reddish brown, tends to come from drains and sewers, and often flies.
The distinction matters because German cockroaches are treated inside the kitchen voids, while American cockroaches usually need the drains dealt with.
Why they keep coming back
The eggs survive
A single female German cockroach carries an egg case containing up to 40 eggs, and she keeps it attached until it is nearly ready to hatch. Spraying kills the adults you can see. The next generation arrives a fortnight later.
You are treating the wrong place
Cockroaches spend most of their lives crammed into warm, dark voids: behind the fridge motor, under the sink, inside cabinet carcasses, around the cooker. Spraying the floor where you saw one does nothing to the population.
They are coming from next door
In flats they travel through shared plumbing and service ducts. A perfectly treated kitchen will be reinfested from the unit above if nothing is done there.
What actually works
Gel bait is the main tool. It is placed inside the voids where they shelter. They feed, return to the harbourage, and the effect spreads through the population including the ones nobody sees. This is why bait outperforms spraying.
Residual spray goes at the edges: skirting, cracks, service ducts, drain surrounds. It catches anything moving between rooms.
Drain treatment matters where American cockroaches are involved.
What does not work is a can of aerosol. It scatters a colony into neighbouring rooms and makes the professional job harder.
What you can do to keep them away
- Fix dripping taps and leaking traps. They need water more urgently than food.
- Store dry goods in sealed containers rather than open packets.
- Empty the bin nightly and wipe under it.
- Clean behind and under the cooker and fridge, not just around them.
- Break down cardboard deliveries outside. Cartons are a common way infestations arrive.
- Seal gaps around pipe entries under the sink.
If you run a restaurant or a food business
Do not wait. Cockroaches in a food business are a compliance problem as well as a pest problem, and the reputational damage from one customer photograph outlasts the infestation by years. Treatment can be scheduled outside trading hours using bait rather than heavy spray in food areas, so you do not lose a day.
Get it treated properly
Send us a photo of what you are seeing and where. See our cockroach fumigation service for how the treatment works and what is included.
