Spotting a cockroach in your kitchen can be unsettling, but it doesn’t always mean you have a serious or minor problem. Because cockroaches are good at hiding, one sighting could be just the beginning. Learning the early warning signs helps you act fast and stop a small issue from turning into a bigger one.
This guide explains the five main signs of a cockroach infestation. By knowing what to look for and where to check, you can protect your home from these tough pests. We will cover the physical evidence they leave and the smells they cause, so you can spot and handle an infestation before it spreads.
Where Do Cockroaches Hide?
Before you look for signs, it helps to know where to search. Cockroaches are active at night and prefer dark, damp places with shelter. (Council, 2025) During the day, they hide in spots that keep them safe and close to food and water. If you see a cockroach during the day, their usual hiding places may be too crowded, often indicating a larger infestation. (Signs of a Cockroach Infestation, n.d.)
Start your search in these common roach hotspots:
- Kitchens: Check behind and under appliances like refrigerators, stoves, and dishwashers. Look inside cabinets, particularly in dark corners and under the sink, where plumbing can create moisture.
- Bathrooms: Leaks and moisture make them a prime spot for cockroaches. Check under sinks, behind toilets, and inside bathroom cabinets.
- Basements and Crawl Spaces: These areas are often dark, damp, and cluttered, offering plenty of hiding places.
- Hidden Cracks and Crevices: Cockroaches can flatten their bodies to squeeze into surprisingly tight spaces. (Jayaram & Full, 2016, pp. 1743-1748) Look behind wallpaper, inside wall cracks, under rubber mats, and even within the motors of large appliances.
Five Telltale Signs of a Cockroach Infestation
Now that you know where they like to hide, here are the top five signs that confirm you have a cockroach problem.
1. Cockroach Droppings
One of the most common and reliable signs of a cockroach infestation is their faeces. (Lai, 2017) The appearance of the droppings depends on the size of the cockroach.
- Small Roaches: Leave droppings that look like black pepper or coffee grounds. You may find these tiny bits on countertops, in drawers, or on shelves.
- Large Roaches: Leave dark, cylinder-shaped droppings that may have ridges on the sides.
The amount of visible faeces is often a good indicator of both the size and duration of the infestation. (Cockroaches, 2025)
2. Unpleasant Odors
A strong, unpleasant smell with no clear source can mean you have many cockroaches. Some types give off chemicals that create a distinctive odour, often described as strong, oily, or musty, which gets worse as the infestation grows. Dead cockroaches are also under appliances. (Why can I smell cockroaches?, 2025) If you notice a strange smell that will not go away, especially in the kitchen or bathroom, check for other signs.
3. Cockroach Egg Cases (Oothecae)
Finding cockroach egg cases, called oothecae, means roaches are not only present but also breeding in your home. These small, oval cases can hold many eggs. (Cockroach Exterminator in Michigan | Creature Control, 2024) They are usually brown or dark and are found in hidden places where they are safe.
Look for oothecae in areas like:
- Behind furniture
- In the spaces between books on a shelf
- Taped to the underside of drawers or shelves
- In cracks and crevices
Finding even one egg case means new roaches could soon hatch, so it is essential to act quickly. (COCKROACH EGG CASES – ARE THEY OLD OR NEW?, 2021)
4. Smear Marks
In damp areas, cockroaches can leave dark, uneven smear marks. You will often see these on walls, baseboards, or in corners where they rest or move. These marks appear as roaches crawl over surfaces and drag their bodies. (Signs of a Cockroach Infestation, 2024) Look for these marks near places where you think they might be hiding, especially in kitchens and bathrooms.
5. Shed Skin
Cockroaches shed their skin several times as they grow. These shed skins are light brown, brittle, and look like empty cockroaches. Finding them is a clear sign that roaches are growing in your home. (Cockroach Infestation: Signs, Risks, and Removal Solutions, 2023) You will usually find them near where roaches nest, such as under sinks, inside cabinets, and behind appliances.
Protect Your Home from Cockroaches
Spotting any of these signs is a clear call to action. A cockroach infestation can grow quickly and poses health risks by spreading bacteria and triggering allergies. (Cockroaches, n.d.) While minor issues can sometimes be handled with thorough cleaning, sealing entry points, and removing food and water sources, established infestations are notoriously difficult to eliminate on your own. (Why DIY Cockroach Control Often Fails, 2025)
If you believe you have a cockroach problem, contacting a professional pest control service is the most effective way to handle it. (Bennett et al., 2024, pp. 1234-1245) Experts can identify the species, locate the source of the infestation, and implement a targeted treatment plan to eliminate the pests for good. Don’t let a minor problem turn into a major headache—take action at the first sign of trouble.
