Pest insect · Blattella germanica / Blatta orientalis · Last updated 24 August 2026
Cockroaches
The German cockroach (Blattella germanica) resists common insecticides. 1 female lays 4 to 8 egg cases of 30 to 40 eggs. In optimal conditions (25 °C), a generation develops in 60 days.
On site within 24h · Re-intervention guarantee if the treated pest reappears
Nocturnal and heat-loving, the cockroach concentrates in kitchens, pipework and electrical panels. It contaminates food and surfaces (salmonellosis, gastroenteritis) and triggers respiratory allergies in chronically exposed occupants.
Identify
Signs of infestation
- Black dot-like droppings, 1 to 2 mm, concentrated under the sink, behind the fridge and in cupboard corners
- Slightly sweet, musty smell in cupboards or damp areas
- Brown egg cases (oothecae), 6 to 10 mm, stuck to surfaces, each holding 30 to 40 eggs
- Transparent shed skins (exuviae) in cracks and behind skirting boards
- Yellow-brown stains left on joints, cardboard and food packaging
Where it's found
Nocturnal and heat-loving, cockroaches concentrate in areas with constant warmth and moisture: under the dishwasher, inside electrical panels, behind hobs, tile joints and cracks. Active by night, they stay hidden by day: an infestation is often well established before it's noticed.
Impact
Associated risks
Health risk
A documented vector of Salmonella, E. coli and staphylococci via its legs and droppings. Its shed skins trigger chronic respiratory allergies in people repeatedly exposed.
Food contamination
A single pass over food surfaces is enough to contaminate them. Storage, worktops and dishes are all exposed, with no visible sign of contamination.
Regulatory impact
In catering or the food industry, a cockroach sighting is an immediate FASFC non-compliance and can trigger an administrative activity suspension.
Compare
Insecticide gel or thermal fogging?
| Criterion | Insecticide gel | Thermal fogging |
|---|---|---|
| Re-entry delay | No need to leave | About 4h depending on the technique |
| Application | Targeted points in cracks, corners and passageways | Insecticide mist diffused throughout the whole room |
| Target | Hidden individuals and egg cases, by ingestion | Insects directly exposed to the mist |
Good practice
Prevention
- 01Seal every crack and tile joint in the kitchen, the main entry and refuge point
- 02Remove sources of standing water: a leak under the sink, condensation behind the fridge, a washing machine drip tray
- 03Store flour, sugar and cereals in airtight jars, never in their original packaging
- 04Systematically inspect parcels, cardboard boxes and second-hand appliances before bringing them indoors
- 05Empty bins every evening in a tightly sealed bag: an open bag is enough to feed a colony overnight
Frequently asked questions
What you're asking
Why do cockroaches come back after treatment?
Contact sprays kill the visible adults but not the eggs (which resist insecticides). A professional treatment uses ingestion gels that reach hidden individuals and egg cases. A second check on day 14 is often needed for heavy infestations.
Do cockroaches transmit diseases?
Yes. The cockroach carries Salmonella, E. coli and several staphylococcus strains. Its droppings and moults trigger chronic respiratory allergies. In food service, its presence means immediate FASFC non-compliance.
Do I have to leave my home during treatment?
For an insecticide gel treatment, no departure is needed — the gel is applied at targeted points in cracks and crevices. For thermal fogging, a 4-hour absence may be required depending on the technique used.
cockroaches problem?
Intervention within 24h, guarantee included.