Why do German cockroaches keep coming back after a spray?
German cockroaches breed quickly and hide in cracks as narrow as 1/16 inch, so a spray usually reaches only the roaches that are exposed. Egg cases and nymphs hidden in walls survive and restock the kitchen. Bait placed in the harborage, plus sealing and sanitation, is what actually shrinks the colony.
Over-the-counter foggers and repellent sprays can make things worse by pushing roaches deeper into walls and spreading them to nearby rooms. They can also contaminate the very bait stations a technician later places.
If you have already sprayed, tell the technician which product you used and where. It shapes which baits are placed and whether repellent residue has to be avoided.
Are cockroaches a health problem, not just a nuisance?
Yes. UC IPM identifies cockroach allergens as an asthma risk, especially in multi-unit housing. Roach droppings, shed skins and body fragments collect in kitchens and bedrooms. Children and people with asthma are the most affected, so getting rid of roaches is part of reducing allergen exposure, not only appearance.
Cleaning helps but does not replace treatment. Sweeping up droppings and wiping cabinets lowers the allergen load once the colony is controlled. Without treatment, the stock of roaches simply rebuilds it.
How do roaches get into Sacramento apartments and older homes?
Mostly through shared walls, pipe chases, laundry rooms and cardboard boxes, grocery bags and used appliances carried in. Because the German cockroach squeezes through gaps of 1/16 inch, a loose escutcheon plate, a gap behind a cabinet or an unsealed pipe penetration is enough.
Multi-unit buildings such as the apartments and converted houses found in downtown, Midtown and rental areas share plumbing and walls, so a neighbor's colony can become yours. Tell the property manager promptly, because treating one unit alone often does not stop movement between units.
Our general pest control service is a good follow-on once the roaches are under control, to keep the exterior barrier and the sealing in good order.
What can I do before the technician arrives?
Do not spray or fog. Clear the sink area, empty the cabinets you can, wash dishes, store food in sealed containers and take out trash. Fix visible leaks. Leave a clear path to the under-sink and appliance areas so the technician can place bait where roaches actually shelter.
Do not wash out cabinets the day after bait is placed, since that removes it. Ask the technician how long the product should be left alone, and keep pets and children away from bait placements as the label directs.
How do I know the roaches are really gone?
Activity falls first, then stops. You see fewer roaches in daylight, the sticky monitors the technician placed catch fewer each visit, and baits are eaten more slowly. A kitchen with no sightings and empty monitors at the follow-up visit is a good sign, though checking again a few weeks later is wise.
Roaches that appear only at night are hard to count, so the monitors do the counting for you. Ask the technician to leave a note in the written report of how many were caught at each location, so a rise at one spot can be traced to a leaking trap or a neighboring unit.
If you still see roaches after the planned visits, say so at once. A colony in a wall void behind a shared kitchen or a neighbor's unit may need a different approach, such as treating the adjoining space or sealing a pipe chase.