Is Your Home Hiding a Cockroach Problem? Here's How to Tell

Nobody wants to think about cockroaches. But here's the uncomfortable truth — by the time most homeowners realize they have a problem, the infestation is already well underway.

Cockroaches are masters of staying hidden. They squeeze into the tiniest cracks, avoid light, and only come out when they feel safe. That means you could have dozens — or even hundreds — living in your walls, under your appliances, or behind your cabinets without ever seeing a single one.

The good news? They always leave clues. Knowing what to look for can help you catch an infestation early, before it spirals into a full-blown crisis. Here's a complete guide to spotting the warning signs in your home.

Why Cockroaches Are So Hard to Spot

Before we get into the signs, it helps to understand why roaches are so difficult to detect in the first place.

Cockroaches are nocturnal insects. They spend their days hiding in dark, warm, and humid spaces, and come out at night to search for food and water. Unless you're turning on lights in the middle of the night, you're unlikely to catch them in the act.

They're also incredibly fast. The moment a light switches on, they scatter and disappear into cracks and crevices within seconds. Their flat bodies allow them to squeeze through gaps as thin as a few millimetres — spaces you wouldn't even notice exist.

This is why most people discover an infestation through indirect signs rather than by seeing roaches themselves. Learning to recognize these signs is one of the most important things you can do as a homeowner.

Top Warning Signs of a Cockroach Infestation

1. Droppings in Hidden Areas

Cockroach droppings are one of the earliest and most reliable signs of an infestation. Depending on the species, they can look like tiny black pepper flakes, coffee grounds, or small dark cylinders with ridged edges.

You'll typically find droppings in areas where roaches spend the most time — under sinks, inside kitchen cabinets, behind the refrigerator and stove, along baseboards, and in bathroom vanities. The more droppings you find, the more active the infestation likely is.

Make a habit of checking these hidden spots regularly, especially if you've recently moved into a new home or noticed any other warning signs.

2. A Musty or Oily Smell

Cockroaches communicate through chemical signals called pheromones, and these pheromones have a very distinct smell. Many people describe it as musty, oily, or slightly sweet — and it's not something you'd easily mistake for anything else once you know what to look for.

If you walk into your kitchen, basement, or bathroom and notice an unpleasant odour that you can't quite explain, don't brush it off. A strong cockroach smell often indicates a large or long-standing infestation. In severe cases, the smell can even penetrate into food stored in the area, making it unsafe to eat.

3. Egg Casings (Oothecae)

Cockroaches don't lay individual eggs — they produce egg cases called oothecae. These are small, capsule-shaped structures, usually brown or reddish in colour, that contain multiple eggs at once. A single ootheca can hold anywhere from 10 to 50 eggs depending on the species.

Finding even one of these egg cases is a serious warning sign. Roaches typically hide their oothecae in sheltered, out-of-the-way spots like behind furniture, inside drawers, in closets, behind wall panels, or near plumbing. Crack open a flashlight and check these areas carefully.

4. Smear Marks Along Walls and Floors

In areas where moisture is present, cockroaches leave behind dark, irregular smear marks as they travel. These marks are caused by their bodies dragging along surfaces, and they often appear as brownish streaks along the edges of walls, near pipe openings, or on the floor around damp areas.

Check around your water heater, under sinks, along basement walls, and near any area with persistent moisture. Smear marks are a strong indicator that roaches are using these paths regularly.

5. Shed Skins

As cockroaches grow from nymphs into adults, they shed their outer shells multiple times in a process called moulting. These shed skins — also called exuviae — look like hollow, papery cockroach shells. They're translucent or light brown and can often be found in the same areas where roaches hide.

If you're finding shed skins in your home, it means roaches have been living there long enough to go through multiple growth stages. That's a sign of an established infestation, not just a random visitor.

6. Damage to Food Packaging and Materials

Cockroaches will chew through cardboard, paper, and thin plastic packaging to get to food. If you're noticing gnaw marks or small holes in food boxes, bags of flour, or stored pantry items, roaches could be the culprit.

They're not picky eaters either. Beyond food, cockroaches will chew on book bindings, wallpaper, leather, and even soap. Any unexplained damage to household materials is worth investigating.

7. Seeing Live Roaches During the Day

This one is significant. Because cockroaches are naturally nocturnal and avoid humans, spotting one during daylight hours usually means the infestation has grown large enough that competition for hiding spots is forcing some roaches out into the open.

If you're seeing roaches during the day — especially in well-lit areas — take it as a serious red flag. The population has likely grown well beyond what's visible to you.

Where to Check in Your Home

Cockroaches gravitate toward specific environments. Focus your inspection on these areas:

Kitchen: Behind and under the refrigerator, under the stove, inside cabinet hinges and drawer slides, around the dishwasher, and near the garbage area.

Bathrooms: Under the sink, around pipe penetrations through the wall, inside the vanity cabinet, and near the toilet base.

Basement and Laundry Room: Along the walls, near the water heater, around dryer vents, and in any area with persistent dampness.

Other Areas: Inside cluttered storage closets, behind large furniture that rarely gets moved, and around any cracks in walls or floors where pipes enter.

Why You Shouldn't Wait to Take Action

Cockroaches reproduce at an alarming rate. A single female German cockroach — the most common species found in Canadian homes — can produce hundreds of offspring in her lifetime. Under the right conditions, a small group of roaches can grow into a colony of thousands within just a few months.

Beyond the sheer numbers, cockroaches pose real health risks. They carry bacteria like Salmonella and E. coli on their bodies and legs, contaminating any food or surface they touch. Their shed skins and droppings can also trigger allergies and worsen asthma symptoms, particularly in children and elderly individuals.

The longer an infestation goes untreated, the harder — and more expensive — it becomes to eliminate. What might take one professional treatment to resolve early on could require multiple visits and more intensive methods if left to grow.

What You Can Do Right Now

While you're figuring out your next steps, there are some things you can do immediately to limit the problem:

• Store all food (including pet food) in sealed, airtight containers
• Fix any leaking pipes or faucets — cockroaches need water to survive
• Clear out clutter, especially in storage areas and basements
• Seal gaps around pipes, baseboards, and entry points with caulk
• Take out the garbage regularly and keep bins tightly closed
• Clean under and behind appliances where grease and crumbs accumulate

These measures can slow the spread, but they won't eliminate an active infestation on their own. Cockroaches that have established nesting sites inside your walls or under flooring require targeted, professional treatment to fully eradicate.

Know When to Call a Professional

If you've spotted any of the signs above — droppings, egg cases, shed skins, a persistent smell, or live roaches — it's time to stop guessing and get expert help.

Professional pest control technicians have access to treatments and tools that aren't available over the counter. More importantly, they know exactly where to look and how to target the source of the infestation rather than just the roaches you can see.

For a deeper look at what to watch for and how professionals approach the problem, check out this detailed guide on identifying the signs of a cockroach infestation in your Bradford home.

Don't Let It Go Any Further

Cockroaches don't go away on their own. Every day you wait is another day they're multiplying, spreading bacteria, and making themselves more at home in yours.

If something doesn't feel right — a strange smell, unexplained droppings, or a single roach spotted in your kitchen — trust your instincts. Contact a licensed pest control professional today and get a thorough inspection done before the problem gets any bigger.

Your home should be a safe and comfortable place. Take action now and make sure it stays that way.