German Cockroaches: How to Tell and How to Get Rid of Them

German cockroaches are the small, light brown cockroaches that turn up in Melbourne kitchens and bathrooms. They are the hardest household cockroach to get rid of, because they breed quickly and hide in places sprays never reach. The fix is targeted baiting at the hiding spots, not more spraying.

How do I tell if I have German cockroaches?

German cockroaches are about 12–15mm long, light brown, with two dark parallel stripes just behind the head. They are almost always found indoors, near food, water and warmth.

Better Health Channel describes German cockroaches as smaller and brown, and American cockroaches as large. If yours are large, dark and coming in from outside or the drains, you are probably dealing with a different species, and the treatment changes.

What are the signs of a German cockroach infestation?

The usual signs are small droppings like ground pepper in drawers and cupboards, a musty smell, and egg cases behind appliances. Seeing them during the day often means the population has grown large.

• Droppings like pepper or coffee grounds along cupboard edges and in drawers
• Brown egg cases behind the fridge, dishwasher or under the sink
• A stale, musty smell in the kitchen
• Cockroaches scattering when you turn on the light at night
• Activity inside appliances, around hinges and in cupboard voids

Why are German cockroaches so hard to get rid of?

They reproduce fast and hide deep. A female lays between 10 and 40 eggs at a time, and around 30 batches in her lifetime.

The egg cases protect the next generation from most surface sprays, and the adults live in cracks, voids and appliance motors you cannot reach. Kill the ones you see and the hidden population simply replaces them.

Are German cockroaches dangerous?

They are a genuine health concern in food areas. Better Health Channel notes cockroaches are believed to spread diseases including salmonella and gastroenteritis, and can also trigger allergies.

That is why kitchens, food businesses and homes with young children are worth treating quickly rather than living with.

How do you get rid of German cockroaches yourself?

Start by cutting off food and water, then use baits rather than sprays. Baits work because the cockroach carries the poison back to the nest.

• Clean under the fridge, stove and other movable appliances
• Store food in sealed containers and never leave dishes overnight
• Fix dripping taps — cockroaches need a steady water supply
• Seal gaps in skirting boards and inside cupboards
• Clear out stacked cardboard boxes and paper
• Do not spray surface insecticide over baits — it drives cockroaches away from the bait

When should I call a professional?

Call a professional when activity keeps returning after a few weeks of good hygiene and baiting, or when you see cockroaches during the day. Better Health Channel advises that heavy infestations need a licensed pest control operator.

A professional treatment identifies the species first, then places gel bait at the actual harbourage points inside cupboard voids, appliance cavities and behind fittings. Units with shared walls may need neighbouring units treated too, or the problem moves back in.

How much does cockroach control cost in Melbourne?

General pest control with 4S Pest Control starts from $129, and cockroaches are included in a general treatment. Larger infestations or units with shared walls may need extra work, and we confirm the price in writing before we book.

See our cockroach control service, read what attracts pests indoors, or call 0412 412 139 for a free quote.

Related reading: why rat control matters and the damage harvest mites can do.