Cockroaches are the most common pest complaint in Nairobi homes, apartments and restaurants. A single female German cockroach can produce up to 400 offspring in her lifetime — which means a small problem becomes a large one very quickly.
The Two Main Cockroach Species in Nairobi
Understanding which species you're dealing with is the first step to effective treatment:
- German Cockroach (Blattella germanica) — The most problematic species in Nairobi kitchens. Small (12–15mm), fast-breeding, and resistant to many over-the-counter sprays. Usually found inside, near food and water sources.
- American Cockroach (Periplaneta americana) — Larger (35–40mm), commonly found in drains, sewers and the ground floor of buildings.
Warning Signs of an Infestation
- Seeing cockroaches during the day (suggests a heavy infestation — they normally hide in daylight)
- Small dark droppings resembling coffee grounds in kitchen cupboards and behind appliances
- A musty, oily odour in enclosed areas like under the sink
- Egg cases (oothecae) in corners or behind picture frames
- Smear marks on surfaces near water sources
Important: If you see cockroaches during the day, you likely have a significant infestation. Cockroaches are nocturnal by nature — daytime sightings mean hiding spaces are overcrowded.
Why DIY Sprays Often Fail
Most supermarket cockroach sprays use a knock-down insecticide that kills on contact but has little residual effect. Worse, repeated use of the same active ingredient causes resistance — the next generation becomes harder to kill.
Gel bait, which professional pest controllers use, is far more effective. Cockroaches are attracted to the bait, eat it, return to the nest, and then the active ingredient spreads to other cockroaches through their droppings and cannibalism.
Professional Treatment: What to Expect
- Inspection — Identifying harbourage points, species, and infestation level
- Gel Bait Application — Applied inside cabinets, behind appliances, and in all cracks and crevices
- Residual Spray — Applied to skirting boards and entry points
- Crack & Crevice Treatment — Injecting insecticide into hidden harbourages
- Follow-Up — We return within 30 days if needed at no additional charge
Prevention Tips
- Store food in sealed containers — open packets invite cockroaches
- Fix leaking pipes and taps — cockroaches need water to survive
- Seal gaps around pipes, electrical conduits, and skirting boards
- Empty kitchen bins daily and keep areas under sinks dry
- Consider quarterly professional treatments for restaurants and commercial kitchens
Need Professional Help?
Kowa Pest Solutions is Nairobi's PCPB-licensed pest control expert. Same-day service available across Nairobi.