German cockroaches

What German cockroaches look like

German cockroaches are the fast-breeding indoor kitchen species, and they are the one cockroach that genuinely lives with you rather than wandering in from outside. Adults are small, roughly 13 to 16 mm, light brown to tan, with two dark parallel stripes running down the shield behind the head. That striped shield is the identification feature. They have wings but rarely fly. Nymphs are darker, almost black, with the same pair of stripes and a pale band across the back. The egg case is a pale brown purse the female carries at the end of her abdomen until it is nearly ready to hatch, which protects it and is part of why numbers climb so fast. They are much smaller than American, Oriental or smoky brown cockroaches, all of which are outdoor and drain-associated species.

Signs you have German cockroaches

• Droppings that look like pepper. Dark specks and smears in cupboard corners, drawer runners, under the sink and along shelf edges.
• Roaches when you turn on the light. Insects scattering from counters, the stove or the sink at night is a sign numbers are already high.
• A musty smell. A sweet, oily, musty odour in a kitchen or bathroom when the population is established.
• Egg cases and shed skins. Small pale brown capsules and papery skins behind appliances, in cabinet hinges and in cardboard.
• Warm appliance harbourage. Activity in the motor housing of the fridge, the dishwasher, the microwave, the kettle base and the coffee machine.

Why German cockroaches come indoors

They do not come in from the garden. German cockroaches cannot survive Canadian winters outdoors, so they are carried in. The usual routes are used appliances and furniture, cardboard boxes and grocery packaging, luggage, second-hand electronics, shared laundry rooms, and movement through wall voids and plumbing chases from a neighbouring unit. Once inside they need only warmth, moisture and crumbs, so kitchens and bathrooms suit them. They breed quickly, each female producing repeated egg cases with dozens of eggs, which is why a few insects become a serious problem in a matter of months. They are a genuine health concern, because they carry bacteria onto food surfaces and their droppings and shed skins are a recognised trigger for asthma and allergies.

How to keep German cockroaches out

• Inspect used appliances, furniture and electronics before they come into the home, and check the motor and hinge areas.
• Break down and remove cardboard promptly, since corrugated card is ideal harbourage and a common way they travel.
• Keep kitchens dry and clean overnight: no dishes in the sink, sealed bins, wiped counters, pet bowls lifted.
• Fix leaks under sinks and around dishwashers, because they need a water source more than a food source.
• Seal gaps around pipes, behind cabinets and at shared walls, which matters most in apartments and condos.

How GO! Pest Control treats German cockroaches

• Inspection. We inspect kitchens, bathrooms, appliance voids and cabinet interiors, and place monitors to show where the population is concentrated and how large it is.
• Treatment. We use gel baits in harbourage areas combined with an insect growth regulator to stop nymphs maturing. We avoid broad surface spraying, which scatters the insects and drives them into voids.
• Follow-up. German cockroach work almost always needs more than one visit. We return to read the monitors, re-bait and treat any new harbourage we find.
• Advice. We give you a clear preparation and sanitation list, and in apartments and condos we advise on checking adjoining units, since untreated neighbours will reinfest.

We are licensed, insured and bonded, and we work in homes, apartments, condos and businesses across the Toronto GTA, Ottawa and Hamilton.

Common questions about German cockroaches