A dark insect crossing the kitchen doesn't mean an infestation. Several common species in Belgium look like a cockroach at first glance without being one — the reverse confusion also happens, and sometimes delays a treatment that's actually needed.
Insects most often mistaken for a cockroach
The woodlouse isn't an insect but a land crustacean: segmented grey-brown body, rolls into a ball when touched, lives in damp spots (cellars, flowerpots, under stones). Doesn't climb walls, never goes near food.
The earwig has distinctive pincers at the tip of its abdomen — a feature no cockroach has at any stage. Drawn to light in the evening, it wanders in by accident but never settles in a kitchen.
The silverfish is silvery, flat, wingless, fast-moving in damp areas (bathroom, under the sink). Feeds on mould and starch, never on food scraps like a cockroach does.
A large shiny black beetle near a door or window in summer is usually a ground beetle (a garden insect, beneficial, never settles indoors) rather than a cockroach.
Real signs of cockroaches, not a lookalike
The German cockroach (the most common indoors) is 1.3-1.6cm, light brown, two dark bands behind the head, long thin antennae constantly moving — usually seen at night, darts away from light.
A single insect seen once doesn't confirm an infestation — especially if it came in with a delivery, shopping bag or visitor. Several individuals seen at different times, or during the day (a sign of overcrowding pushing them out), is a real signal.
The most reliable sign without a visible insect: small black droppings resembling coffee grounds or pepper, concentrated near water and heat sources (under the sink, behind the fridge, around the dishwasher).
Other common household insects, unrelated to cockroaches
A tiny black insect near a food cupboard points more toward a pantry moth or a weevil — see the dedicated pantry moth article to tell them apart.
An insect found near a beam or solid wood furniture, with a small round hole and fine sawdust, points to a woodworm rather than a cockroach — the two look nothing alike side by side.
The odd ant in the kitchen isn't an early stage of a cockroach infestation: they're two independent pests, treated differently.
When a professional check makes sense
An insect seen once, during the day, with no droppings nearby: keeping an eye on it is enough, no treatment needed.
Several individuals, coffee-ground-like droppings, or a persistent smell near water sources: an inspection confirms the species before any treatment — treating the wrong insect solves nothing and delays the real fix.
Antinox identifies the species on site before proposing a treatment, precisely to avoid a cockroach treatment on a woodlouse or earwig that doesn't need one.
Frequently asked questions
Does a woodlouse at home mean there are cockroaches?
No. The woodlouse is a crustacean, not an insect, it lives in damp spots and never goes near food like a cockroach. Its presence points to a damp area (cellar, flowerpot), not an infestation.
How do I tell an earwig from a young cockroach?
The earwig has clearly visible pincers at the tip of its abdomen, absent in cockroaches at every stage. It's the easiest sign to check at a glance.
Does seeing one insect once mean an infestation?
No, especially during the day and with no droppings nearby. A cockroach infestation shows through several individuals, usually seen at night, and black droppings near water sources.
Should an unidentified insect be treated with a cockroach product?
No — a mistargeted treatment doesn't work on the wrong species and delays the real fix. Identifying the insect first avoids that waste.