Understanding and getting rid of cockroaches once and for all

Also called roaches, these insects are parasites. They evoke a reaction of disgust from most people and are considered harmful intruders… for good reason.

Learn how to recognize their presence, why and how they might have ended up in your home, and what you can do to get rid of them as fast as possible.

What do cockroaches in Québec look like?

There are five main active species of cockroaches in Québec, but the most common one found in the Greater Montreal and South Shore areas is the German cockroach, also called croton bug (Blatella germanica).

The German cockroach has a flat, oval shaped body and is light brown in colour with two dark brown lines on its thorax. Its antennae are long and thin, its legs are also long, and it has two pairs of wings. The adult German cockroach is 10 to 16 mm (3/4 of an inch) long. And even though they have wings, cockroaches are not expert pilots; they fly clumsily and use their wings to parachute themselves onto their next destination.

The brownbanded cockroach (Supella longipalpa) and the oriental cockroach (Blatta orientalis, also called black beetle or water bug) are also active in Canadian households. Their body shape resembles that of the German cockroach.

The brownbanded cockroach is buff-coloured with two light brown lines across its wings. The adult measures 10 to 14 mm long.

The oriental cockroach is dark brown to black in colour, and the adult is 18 to 30 mm (about 3/4 to 1 1/8 of an inch) long.

A cockroach on a piece of wood.

The life of a cockroach

All female cockroaches lay their eggs in a pouch (or a shell) called egg pod or ootheca. However, they don’t all care for their eggs in the same way or lay the same quantity of eggs. The eggs, then the nymphs, become adults in about 100 days; the adult cockroaches will live for up to one year. A cockroach infestation may number in the thousands of individuals.

The female German cockroach lays up to 8 egg pods that each contains up to 40 eggs; the female will carry the egg pod until the eggs hatch. The female of this species of cockroaches is the fastest reproducer in comparison to the other 2 species described below.

The brownbanded cockroach will glue its egg pod (containing about 16 eggs) onto furniture or other surfaces.

The oriental cockroach will lay about 18 eggs into an egg pod and then place the pod inside a fissure, covering it with debris or fecal matter.

Where do cockroaches hide?

Cockroaches can infiltrate any location that offers them food, water, and shelter. They eat practically anything: sweet or mealy foods, dead organisms, paper, glue, textiles, hair, excrements, blood, saliva, etc. They are hardy: they can survive up to 200 days without food and almost 40 days without water.

Most cockroaches shy away from light and spend the day hiding and motionless. They start being active at night as they search for food. Therefore, if you see a cockroach in broad daylight, this means the population has grown to a considerable number.

The German cockroach likes to hide in dark cracks and fissures, where it is warm and humid, for example in kitchen cabinets, under tables, counters, and sinks. It can even slip into an electricity meter or a kitchen appliance.

The brownbanded cockroach prefers warm and dry places like furniture, heating appliances, light fixtures, telephones, picture frames, piled up boxes or debris.

As for the oriental cockroach, it prefers damp areas that are cool: basements, pipework, under flooring. However, beware that in case of need, it will easily tolerate dryer environments.

Harmful effects

Although they almost never damage building structures, all cockroach species are harmful and represent an undeniable risk to the occupants’ health. How so?

  • They leave their excrements and other secretions directly onto food, which makes it smell and taste bad.
  • They permeate food with a brown liquid that drips out of their mandibles, soiling dishes and giving off a nauseous odour.
  • They carry diseases into areas where food is prepared, because they come from places where they have run in and over all kinds of garbage and rubbish.
  • The debris and excrement they produce can worsen the symptoms of asthma or allergies.

How do I know if I have a problem with cockroaches? Why have they invaded my home?

The presence of a brown, foul-smelling liquid substance on food can be the sign that cockroaches are at work.

If you suspect cockroaches are present, it is possible to detect them with adhesive traps, with or without bait. Talk to our specialists, who will be able to suggest the best products to fight cockroaches.

Place the traps near potential hiding places, such as under the refrigerator, in the cupboards or under the sink. These traps will help you identify which species of cockroach you are dealing with and where it likes to hide.

Many people falsely believe that having a problem with cockroaches is a sign of uncleanliness or negligence – but this is not the case. Cockroaches are experts in the art of travelling undetected! Thanks to their flat and oval shaped body, they can easily slip into all kinds of objects you might bring into the house, such as old furniture, cardboard boxes containing food from the grocery store, empty bottles that have not been properly cleaned, etc.

Once inside your home, it’s child’s play for them to find a hiding place and come out only at night, completely without your knowledge.

Exterminator tips

“The presence of cockroaches is a serious threat to a building’s hygiene. As this insect is visible mostly at night, several months may elapse between the initial infestation and the discovery of a cockroach by an owner or renter. In a multiple-unit residential building, the cockroach will have had plenty of time to lay eggs, using the walls, ceilings and floors to contaminate the other apartments. It will be imperative to carefully clean the apartments and to make sure the counters are free of food or crumbs. Dirty dishes must not be left on counters, especially at night. Dry food stored in the pantry should be stored in airtight containers. Because a cockroach can survive weeks without food, the cleaning operation should also be carried out in coordination with a qualified exterminator’s pest control program.”

Jacques, exterminator at AJS for 30 years.

How can I prevent and eliminate a cockroach infestation?

The measures described below may seem somewhat daunting, but don’t be put off by them. Many people already follow these guidelines in the normal course of their household cleaning routine. Although it can be a challenge to remember every single detail, it is totally worth your while to put in the extra effort and attention. That way, even if you are one day faced with a cockroach problem, these measures will contribute to reduce the amount of pesticide that will be required to exterminate an infestation.


  • Store food in airtight containers.
  • Clean grease or other residue from household appliances (refrigerators, stoves, food processors, etc.)
  • Avoid leaving food or food residue on counters, or in sink or floor drains.
  • Do not leave any dirty dishes on the counters or tables, especially at night.
  • Daily dispose of trash in well-sealed plastic bags.
  • Avoid leaving pet food and water at their disposal all day.
  • Vacuum regularly, every day if possible, so as to eliminate food crumbs and cockroach eggs.
  • Fill and seal fissures in walls and floors using the appropriate filler (plaster, silicone, etc.)
  • Insulate any piping that produces a significant amount of condensation.
  • Repair any leaking pipes or faucets.
  • Keep the washroom well ventilated.


  • Steam clean furniture, toys or handicrafts, if they are resistant to heat and humidity.
  • Vacuum regularly to eliminate food sources, cockroaches and their eggs. Make sure to immerse the vacuum bag in soapy water.
  • Freeze infested items at a temperature of -8 °C (17.6 °F) for at least 24 hours (preferably for up to one week).
  • Use pesticides. This is often described as a solution of last resort. Unfortunately, most people grappling with a cockroach problem eventually choose this option. All warnings and instructions shown on product labels must be read and followed before using any chemical that is manufactured and sold for the purpose of exterminating cockroaches.
  • Use the services of a pest control professional who has been certified by the Québec Ministry of the Environment.

An exterminator who can help you get rid of cockroaches

Your AJS Extermination professional is certified and authorized to use products that have been registered and approved by the provincial government to eradicate all presence of cockroaches from your home. He has the knowledge and training in order to combine the use of traps, bait, and pesticides depending on your individual situation, while being mindful of the health and safety of all occupants.

The following steps should be followed to ensure the success of the treatment applied by your exterminator:

  • Vacuum all carpeting, rugs and upholstered furniture. Immediately after, dispose of the vacuum bag in an airtight bag and discard it outside the building. Empty recycling bins, newspapers, cardboard boxes and paper bags. Clean behind and under the stove and refrigerator to remove all traces of grease.
  • Wash all shelving in kitchen cupboards and leave them empty.
  • Keep children and pets away during the treatment.
  • Plan to leave your premises during the treatment and to return after 6 hours. On your return, if possible, open the windows for 20 minutes. It is also important not to walk barefoot on the treated areas for 48 hours after the treatment.

If you are faced with a cockroach problem and you live in Montréal or the South Shore, our specialists can help you eliminate the problem once and for all.

Why trust our pest control services?

Choosing an exterminator isn’t something you can do lightly! Offers abound in the extermination sector, but a few important factors should be part of your research before you contact an exterminator: Do they offer a guarantee on their work? Does the company have sufficient experience? Is it possible to talk with a technician to obtain advice on prevention in order to avoid another infestation?

Don’t hesitate to call us — we’ll be glad to explain why thousands of customers value our service!

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