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What Actually Attracts Cockroaches to Your Montreal Apartment?

Published April 7, 2026 · Extermination DMP

Let me start by killing the biggest myth in pest control: cockroaches are not attracted to dirty homes. They are attracted to resources. Specifically three things: moisture, warmth, and food — in that order.

The cleanest apartment in Montreal can have cockroaches if it shares walls with a unit that has a leaking pipe, if the building has poor waste management, or if the previous tenant left behind an established colony.

Understanding what actually attracts them is the first step toward getting rid of them.

The Three Attractants — In Order of Importance

1. Moisture (The #1 Factor)

Cockroaches can survive weeks without food but only days without water. Moisture is the single most important attractant.

In Montreal apartments, the main moisture sources are:

Fix every leak. Wipe every surface dry at night. Use a bathroom fan after showers. This single step reduces cockroach populations more than any spray.

2. Warmth

German cockroaches — the species you almost certainly have in a Montreal apartment — thrive at room temperature. They cannot survive Canadian winters outdoors. Your heated apartment is their permanent home.

They gravitate toward the warmest spots:

You cannot eliminate warmth from your home. But knowing where they congregate tells you where to focus treatment.

3. Food

Cockroaches eat almost anything organic. Their definition of food is broader than yours: A spotlessly clean kitchen reduces their food supply but does not eliminate it. They find nutrition in residues invisible to you.

Building-Level Factors You Cannot Control

Shared Plumbing

In Montreal apartment buildings, plumbing stacks run vertically through every unit. Cockroaches travel along these pipes from floor to floor. The gaps around pipes where they enter each unit are highways.

Garbage Room

A building garbage room with overflowing bins, food residue, and poor ventilation is cockroach paradise. The insects breed there and migrate to nearby units.

Adjacent Units

Your neighbor's cockroach problem is your cockroach problem. In multi-unit buildings, cockroaches move freely through shared wall cavities, electrical conduits, and plumbing penetrations. You can maintain a perfect kitchen and still have cockroaches coming through the wall from next door.

Building Age

Older Montreal buildings (pre-1970) have more harborage points — cracks, gaps, void spaces — than modern construction. The gap behind a 1950s medicine cabinet or the space inside a plaster-and-lath wall provides exactly the dark, undisturbed environment cockroaches prefer.

What You Can Control

In Your Unit

With Your Landlord

Frequently Asked Questions

Can cockroaches come through the drain?

Oriental cockroaches (the larger, darker species) can come up through floor drains, especially in basements. German cockroaches (the smaller, lighter ones) do not typically travel through water-filled drain traps. If you are seeing cockroaches near drains, it is more likely they are traveling along the outside of drain pipes through wall cavities.

If I keep my apartment perfectly clean, will the cockroaches go away?

Cleanliness helps but does not solve the problem alone in a multi-unit building. If the source is a neighboring unit, the garbage room, or the building infrastructure, cockroaches will continue entering your unit regardless of how clean it is. You need building-wide treatment plus your personal sanitation efforts.

Got a pest problem?

Extermination DMP serves Montreal, the South Shore, Laval & the West Island — 24/7.

Call 438-879-5706