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Controlling them takes patience and cooperation. A licensed exterminator identifies the species, finds where they shelter, relies on baits and gels placed in cracks and crevices rather than broad spraying, and comes back to monitor. The household cuts off food, water and clutter, and in a multi-unit building the landlord coordinates treatment of neighbouring units so the insects don't simply move next door and return.
This page covers species, signs, health concerns, baits versus sprays, apartment buildings and landlord obligations, and the cleaning and sealing that keep cockroaches from coming back.
Cockroach species found in Canadian homes and apartments
Identification tells the technician where to look and what to use. Health Canada describes the German cockroach as one of the most common household cockroaches in the world, about 1.3 to 1.6 cm long, and notes that it is found in buildings as far north as Nunavut. A few other species turn up less often.
- German cockroaches: small and light brown, with two dark stripes behind the head; the usual species in apartment kitchens and bathrooms, living entirely indoors near warmth, water and food.
- Brown-banded cockroaches: similar in size, with pale bands across the body, preferring drier, warmer spots higher up, such as inside furniture, behind picture frames and in electronics.
- Oriental cockroaches: larger, dark and shiny, favouring cool, damp basements, floor drains and crawl spaces.
- American cockroaches: the largest and reddish-brown, more common in commercial buildings and sewers than in homes, though they can come up through drains.
Signs of a cockroach infestation: droppings, egg cases and odour
Cockroaches avoid light and people, so seeing them in daytime suggests their hiding places are crowded. Health Canada notes that they gravitate toward the warm, damp conditions of kitchens, bathrooms, basements and plumbing areas, which is where to look.
- Cockroaches scattering when a kitchen light is switched on at night, or dead ones in cupboards and under appliances.
- Droppings that look like ground pepper or coffee grounds in drawers, along shelf edges and behind the fridge and stove.
- Dark smears along cracks, hinges and corners where they rest.
- Egg cases: small brown capsules left in cracks, behind appliances or stuck under furniture.
- A musty, oily odour in cupboards once numbers are high.
- Catches on sticky traps under the sink and along kitchen baseboards, which Health Canada says let you monitor the population and location of roaches.
Cockroach allergens, asthma and food contamination
Cockroaches are more than unpleasant. Health Canada explains that they can contaminate food and spread disease by walking over and excreting on food or food preparation areas after travelling through garbage or sewers. It also notes that people with asthma may have a negative reaction to their droppings and body parts.
Those allergens linger in dust after the insects are gone, so thorough cleaning is part of recovering from an infestation, not only of preventing the next one. If someone in the home has asthma or allergies, mention it before treatment so the technician can plan products and placement, and see a doctor if breathing symptoms get worse.
Cockroach baits and gels vs sprays: what works indoors
Cockroaches spend most of their lives tucked into cracks, so treatment has to reach them there. Health Canada notes that residual crack and crevice products are the most commonly used products registered for cockroaches, and that bait stations in tamper-proof containers kill the insects about 48 to 96 hours after they eat the active ingredient. That delay is why baits go right beside the places cockroaches hide.
- Gel baits: small dabs placed by a technician in hinges, cracks and behind appliances, close to hiding spots and out of reach of children and pets.
- Bait stations: enclosed units that suit homes with children or pets when placed out of reach.
- Crack and crevice treatments: registered residual products applied into gaps rather than across counters and floors.
- Broad sprays and foggers: they kill exposed insects but miss the ones hidden in walls, can drive cockroaches into other rooms and units, and can make nearby baits less attractive.
- Monitoring: sticky traps checked at each follow-up visit show whether numbers are falling and where to adjust.
- Registered products only: look for the Pest Control Products (PCP) number, follow the label and never mix your own.
Cockroaches in apartment buildings: building-wide treatment and landlord obligations
Treating one apartment in isolation often pushes cockroaches into the walls and the units next door, and later back again. Effective programs inspect and treat the affected unit along with the units beside, above and below it, plus shared garbage rooms and service areas. Health Canada's guidance for landlords and building managers calls prevention the best approach, asks them to share the treatment plan with all occupants in advance, including what to do before and after, and to give occupants the name and registration number of the pesticide used. Only professional pest control specialists may use products labelled as commercial class.
In Quebec, the Tribunal administratif du logement lists vermin such as cockroaches among the conditions that can make a dwelling unsanitary, and a tenant can apply for an order to carry out work, a rent reduction, damages or cancellation of the lease. The City of Montréal tells tenants who see cockroaches to inform the landlord right away, preferably in writing, and says the landlord must bring in an extermination company; a tenant who has asked the landlord to act within 10 business days can then request an inspection through 311.
Ontario's Landlord and Tenant Board places pest control among the landlord's maintenance duties, while tenants are expected to keep their unit reasonably clean. When a landlord fails to act, the tenant's remedy is a maintenance application on Form T6.
Sanitation and sealing to keep cockroaches from coming back
Treatment knocks the population down; taking away food, water and shelter keeps it down. Health Canada's advice covers both.
- Clean up spills right away, and don't leave pet food and water out 24 hours a day.
- Vacuum often, including under and behind appliances, and destroy what you collect by placing the vacuum bag in soapy water, as Health Canada suggests.
- Keep food in sealed containers, take out garbage and recycling often and keep the bins lidded.
- Fix dripping taps, leaky drains and condensation under sinks, since water draws cockroaches as much as food does.
- Seal and caulk cracks, crevices and pipe openings, especially under sinks, behind toilets and where pipes pass between units.
- Cut down on cardboard boxes, paper bags and stacks of newspapers, where cockroaches hide and leave egg cases.
- Check grocery boxes, second-hand appliances and furniture before bringing them in.
Cockroaches: frequently asked questions
Do cockroaches mean my apartment is dirty?
Not necessarily. In multi-unit buildings they travel through walls and pipe chases from neighbouring units, so even a spotless kitchen can have them. Crumbs, clutter and leaks do make an infestation worse and harder to treat.
Who is responsible for cockroach treatment in a rental?
The landlord, in both Quebec and Ontario, where pest control is part of maintaining the unit. Tenants should report the problem promptly and in writing, follow the preparation instructions and give access for treatment and follow-up visits.
Why do cockroaches come back after spraying?
Sprays reach the insects in the open, not the ones in walls and deep cracks, and eggs protected inside their cases hatch later. Baits and gels, repeat visits to catch newly hatched nymphs, treatment of neighbouring units and sealing are what break the cycle.
Are cockroach baits safe around children and pets?
Bait stations come in tamper-proof containers and gels go into cracks out of reach, which limits exposure. Use only products with a PCP number, follow the label, and keep stations away from where children play and pets eat.
Can cockroaches make asthma worse?
Health Canada notes that people with asthma may react to cockroach droppings and body parts. Treat an infestation promptly, keep up thorough cleaning afterwards, and talk to a doctor if symptoms change.
Sources
- Health Canada: Cockroaches
- Health Canada: Information on pesticide use for landlords and building managers
- Unsanitary conditions — Tribunal administratif du logement
- City of Montréal: Tenants have the right to a dwelling in good condition
- City of Montréal: Request an inspection of a dwelling
- Maintenance and repairs brochure — Landlord and Tenant Board
Written by the LokalMatch editorial team. Reviewed by Zubair Afzal on September 10, 2026. How we write and check our guides