- Droppings: small dark specks, like ground pepper, in drawers and behind appliances.
- Egg cases: brown capsule-shaped cases near hinges, under sinks and behind the fridge.
- A musty smell in closed cabinets.
- Daytime sightings: cockroaches are nocturnal, so seeing them by day usually means a crowded population.
- Shed skins in corners and cracks.
Sprays from the shop scatter cockroaches deeper into walls. A professional gel treatment works through the colony instead.