Warning signs
- Insects scattering when a light comes on at night
- Pepper-like droppings in drawers, cabinets or under appliances
- Egg cases tucked behind or beneath fixtures
- A musty odor in cabinets or near appliances
- Smear marks in damp areas
Where activity concentrates
Warmth, moisture and food access drive location. That usually means behind refrigerators and dishwashers, under sinks, around motor housings and inside cabinet voids.
Why they come back
Surface sprays reach the insects you see rather than the harborage where the population lives. That gap is the usual reason activity returns after a retail product seems to work at first.