The two most common cockroach species in Singapore HDB flats are the German cockroach and the American cockroach. German cockroaches are small (10-15mm), light brown, and prefer kitchens — they hide in appliances, cabinets, and cracks. American cockroaches are larger (30-40mm), reddish-brown, and often enter via drains and sewers, favouring bathrooms and kitchens. Both species reproduce rapidly and can spread bacteria such as Salmonella and E. coli across food preparation surfaces.
Cockroaches need food, water, and shelter to survive. Remove their food supply by wiping down kitchen surfaces daily, storing food in sealed containers, and not leaving dirty dishes overnight. Empty your rubbish bin daily and keep it sealed. Fix leaking taps and pipes — cockroaches can survive a week without food but only days without water. Don't forget pet food bowls — clear them after your pet finishes eating.
Cockroaches can squeeze through gaps as thin as 3mm. Seal cracks around pipes, skirting boards, and kitchen cabinets with silicone sealant. Install drain covers in bathroom and kitchen floor traps — American cockroaches often enter HDB flats through the sewer system. Check that window screens are intact and fill gaps around air conditioning units. Pay attention to the area behind the refrigerator and stove, where cockroaches often hide and breed.
Cockroaches love clutter — stacks of cardboard, old newspapers, and plastic bags provide perfect harbourage. Declutter your home, especially in the kitchen and store room. Replace cardboard boxes with sealed plastic containers. Keep the area under your sink clean and dry, as the pipe connections there are a common entry point. Regular cleaning behind and under appliances removes the grease and food residue that cockroaches feed on.
For minor issues, cockroach bait stations and gel baits (such as Advion or Maxforce) can be effective when placed in areas where cockroaches travel — under sinks, behind appliances, and in cabinet corners. Avoid spraying insecticide near bait stations, as it can contaminate the bait and make cockroaches avoid it. Sticky traps help monitor cockroach activity and identify problem areas. However, if you see cockroaches during the day or find egg cases (oothecae), the infestation is likely advanced and requires professional treatment.
If DIY methods aren't working, you see cockroaches during daylight hours, or you find multiple egg cases, it's time to call a NEA-licensed pest control professional. Professional cockroach treatment uses commercial-grade gel baits, residual spraying, and insect growth regulators (IGRs) to break the breeding cycle. A single professional treatment combined with good sanitation habits can eliminate even severe infestations. For HDB flats with recurring cockroach problems, ongoing maintenance contracts provide year-round protection.
In HDB estates, cockroaches can travel between units through shared pipes and wall voids. If your neighbours have an infestation, you may see cockroaches even if your own home is clean. In these cases, treating only your unit provides temporary relief — a coordinated approach treating multiple units is more effective. If you're experiencing recurring cockroach problems, speak to your neighbours and consider engaging a pest control service to treat the affected units simultaneously.
