The short answer
The German cockroach is common in Hong Kong kitchens. Key identifiers are a pale-brown body, an adult length of 1.3–1.6cm and two dark parallel stripes just behind the head.
It rarely flies. It hides in warm, damp gaps — behind the fridge motor, inside oven seams, behind the water heater — and can breed quickly.
Record repeated sightings and inspect nearby hiding places. Gel bait and targeted treatment may suit hidden activity better than spraying only the insects you can see.
- Scientific name
- Blattella germanica
- Chinese name
- 德國曱甴
- English name
- German cockroach
Prevention and control source
How to identify a German cockroach
- Size: adults run 1.3 to 1.6cm, nymphs smaller, pale brown to tan.
- The giveaway mark: two dark parallel stripes on the shield just behind the head — the main way to tell it apart from an American cockroach.
- Wings: present but rarely used for flight — it mostly crawls.
- Spotting one alone cannot establish the scale. Record where it appeared, then check nearby for egg cases, droppings or additional insects.
Where do they turn up in Hong Kong homes and shops?
German cockroaches commonly shelter in warm, damp indoor gaps, especially kitchens:
- Behind the fridge or washing machine motor
- Inside oven or microwave seams
- Behind the water heater or extractor fan joints
- Cabinet and counter joints
- Prep counters and cold room doors in food businesses
Why does it matter?
Cockroaches can contaminate food, and their droppings and shed skins contain allergens. Keep food protected and remove food residues and clutter. Seek medical advice for symptoms rather than assuming a cockroach sighting explains their cause.
Does spraying insecticide yourself work?
Treating visible insects may miss harbourages. FEHD describes cleaning, sealing gaps, trapping, residual insecticides and baits as control measures. The choice depends on the premises and product label, not a fixed combination for every job. For a practical comparison, see our cockroach DIY vs professional guide.
How to keep them from coming back
- Keep food sealed and don't leave it out overnight
- Wash dishes right after use — don't leave them overnight
- Clean crumbs from behind the fridge and under the oven regularly
- Don't stockpile cardboard boxes or paper bags in the kitchen — roaches like the corrugated layer inside