German Cockroaches in Montreal Kitchens: The Complete Extermination Guide

Published March 11, 2026 · Extermination DMP

If you flip on your kitchen light at 2 a.m. and see small tan-coloured insects scattering behind the toaster, you are almost certainly looking at German cockroaches. They are the number-one cockroach species found in Montreal apartments and restaurants, and they are notoriously difficult to eliminate without professional help.

Identifying German Cockroaches

German cockroaches (Blattella germanica) are light brown to tan, about 12 to 15 mm long, and have two dark parallel stripes running down the shield behind their head. Although they have wings, they rarely fly. They are often confused with other species, but in Quebec apartments the German cockroach accounts for the vast majority of infestations.

You may also spot their egg cases — small, brown, purse-shaped capsules about 8 mm long. A single female carries one egg case at a time containing up to 40 eggs, and she can produce a new one every few weeks. This is why populations explode so quickly.

Why They Love Montreal Kitchens

German cockroaches need three things: warmth, moisture, and food. A kitchen provides all three in abundance. They hide behind refrigerators, inside microwave vents, under sinks, and inside the crevices of stoves. Montreal's older apartment buildings, with shared plumbing walls and tight unit spacing, allow them to travel freely between units — which is why treating a single apartment often fails to solve the problem.

Health Risks

Cockroach droppings, shed skins, and saliva contain proteins that trigger asthma and allergy symptoms, particularly in children. They also carry bacteria including Salmonella and E. coli on their bodies, contaminating food-preparation surfaces as they forage at night.

Why DIY Sprays Often Fail

Hardware-store aerosol sprays kill the roaches you can see but do almost nothing to the colony hiding in wall voids and appliance motors. Worse, many German cockroach populations in Montreal have developed resistance to common pyrethroids — the active ingredient in most consumer sprays. Spraying can also cause the colony to scatter deeper into walls or migrate to neighbouring units.

Professional Treatment That Works

Effective cockroach extermination uses a combination of gel baits, insect growth regulators (IGRs), and dust formulations applied directly into harbourage areas. Gel baits exploit the roach's social feeding behaviour — when one cockroach eats the bait and dies, others consume its body and are poisoned in turn.

At Extermination DMP, we follow a three-visit protocol for German cockroach infestations: an initial treatment, a two-week follow-up, and a final inspection at four weeks. In multi-unit buildings, we coordinate with property managers to treat adjacent units simultaneously for best results.

Keeping Them Out for Good

• Clean grease from behind and under the stove regularly.
• Fix dripping faucets — roaches need water more than food.
• Store food in sealed containers; never leave dirty dishes overnight.
• Seal gaps around pipes under the kitchen and bathroom sinks with caulk.
• Inspect grocery bags and second-hand appliances before bringing them inside.