Professional Cockroach Extermination

What they look like

A German cockroach is 13 to 16 mm, light brown, with two dark parallel stripes running down the shield behind its head. An oriental cockroach is around 25 mm, very dark brown to near black, and slow-moving. An American cockroach is much larger at 35 to 40 mm, reddish-brown, with a pale figure-of-eight marking on that same shield. Brown-banded cockroaches are small like German ones but carry pale bands across the wings and spread higher up a room, including behind picture frames and inside electronics.

How they reproduce and develop

A female German cockroach carries her egg case until just before it hatches, which protects it from most sprays, then releases around 30 to 40 nymphs. Development to adult takes roughly six to twelve weeks indoors, and a female can produce four to eight egg cases in her life. Several overlapping generations in a warm kitchen is why numbers appear to explode. Oriental and American cockroaches develop more slowly, over several months to a year, but reach much larger sizes.

Where they live and hide

Cockroaches want warmth, moisture, and a tight space that touches their body on several sides. That means motor housings of fridges and dishwashers, the void behind kickboards, cupboard hinges and corners, hollow table legs, cardboard stacked near a warm wall, drain surrounds, and the gap behind wall tiles. Oriental cockroaches prefer cool damp places instead: floor drains, sump areas, crawl spaces, and basement storage.

What they feed on

They are omnivorous scavengers: grease films, food debris, starches, pet food, soap residue, cardboard glue, and even the paste behind wallpaper. Access to water matters more than access to food, so leaks, condensation, and standing water under a sink drive activity more than crumbs do. They feed on each other's droppings, which is what makes gel bait so effective when it is placed correctly.

How they get in and spread

German cockroaches almost always arrive as hitchhikers, in cardboard deliveries, grocery bags, second-hand appliances, restaurant supply boxes, laundry baskets, and moving cartons. In apartments and connected commercial units they also move along plumbing chases, shared wall voids, and service risers. American and oriental cockroaches more often come in from drains, sewer connections, and exterior openings at ground level.

When they are active in Ontario

German cockroaches live indoors in heated buildings and are active all year in Ontario. Oriental and American cockroaches become more visible in late summer and autumn, and after heavy rain when water pushes them out of drains and sewer connections into basements and ground-floor service areas.

Health and property risk

Cockroaches walk through drains and waste and then across food surfaces, carrying bacteria mechanically on their bodies. The better-documented health issue is allergy: cockroach droppings, shed skins, and body fragments are a recognised indoor allergen and a known asthma trigger, particularly for children in multi-unit housing. For food businesses, a visible cockroach can mean a failed inspection and a closure order.

Why one apartment is never the whole job

German cockroaches travel through the gaps around plumbing stacks, along shared wall voids, and behind kitchen and bathroom fixtures. In a building with a riser running through it, the unit that reports cockroaches is frequently not the unit with the source population.

This is why reactive, unit-by-unit treatment is the single most reliable way to keep a building infested for years. Each treated unit clears, then gets recolonised from an untreated neighbour within weeks, and everyone concludes the treatment did not work.

The approach that does work is stack-based: inspect and treat the units above and below the reporting one at the same time, place monitors through the riser to find where the population actually lives, and service the whole set on one schedule. It costs more on the first visit and far less over a year.

Why foggers and sprays make it worse

A fogger or bug bomb releases product into open air, where it settles on surfaces. Cockroaches live inside gaps, motor housings, and voids that the product never reaches, so the population survives almost intact.

Worse, most consumer products are repellent. Cockroaches respond by moving away from the treated area, which means deeper into wall voids, up into ceiling spaces, and into neighbouring rooms and units. A problem confined to one kitchen becomes a problem across a floor.

Broadcast spraying also contaminates gel bait placements. Cockroaches stop feeding on treated bait, which removes the most effective tool available. If you have already sprayed, say so, because it changes how the bait programme has to be set up.

Cockroaches, allergens, and asthma

The health issue with cockroaches is not primarily what they carry on their feet. It is allergen: their droppings, shed skins, saliva, and body fragments accumulate as fine particles in dust and are a recognised trigger for asthma and allergic rhinitis.

The effect is strongest for children in multi-unit housing, where exposure is long-term and the source is often in a neighbouring unit rather than their own. Allergen persists after the insects are gone, so thorough cleaning of affected cupboards, floors, and soft furnishings is part of finishing the job rather than an optional extra.

For anyone in a household with asthma, this is the reason to treat a cockroach problem properly rather than living with a low-level population.

Preparing for a cockroach treatment

Do not deep clean immediately before a gel bait visit. Degreasing every surface right before the technician arrives sounds helpful, but cockroaches that have just lost their food supply behave unpredictably and heavy cleaning can disturb the harbourage we need to find.

Do clear the cupboards and drawers you are asked to, empty and clean under the sink, and make the space behind the fridge, stove, and dishwasher accessible. Those voids are where the population actually lives.

Do fix the water. A dripping tap, a leaking trap, or condensation under a sink matters more to a cockroach population than crumbs do, and leaving it unresolved is the most common reason a bait programme stalls.

After treatment, leave the bait placements alone. Wiping them away because they look untidy removes the treatment.

What a health inspector looks for in a food premises

Live insects in a food preparation or storage area are the obvious finding, but an inspection also looks at evidence: droppings in cupboard corners and on shelf runners, egg cases in hinge recesses, shed skins behind equipment, and staining in appliance voids.

Equally important is the record. A current service log, a site map with numbered monitoring points, dated product records, and a corrective action list showing what was found and what was done about it demonstrate an operation in control. An empty folder and a recent spray does not.

Structural and process items come up repeatedly: gaps under receiving doors, cardboard stored against warm walls, floor drains without maintenance, and equipment that cannot be moved for cleaning. Fixing those is what stops the cycle, and they belong on a ranked action list rather than being treated around indefinitely.