The pests can contaminate food with certain bacterial diseases that result in food poisoning, dysentery, or diarrhea. German cockroaches can be detected by examining the premises after dark with a flashlight. During the day, probing hiding places with a wire or thin wood strip will expose roaches. Household sprays of 0.1 percent pyrethrins applied to hiding places will flush out roaches, sometimes killing them if they contact the spray. Inspect sacks, cartons and boxes, etc., brought into the house, and destroy any roaches.
Sanitation is critical in roach control.
Clean up spilled foods and liquids, avoid leaving scraps of food on unwashed dishes and counter tops, keep food in tightly sealed containers, rinse cans and bottles before putting them in trash and transfer garbage outdoors into roach-proof receptacles. Apply chemicals at roach hiding places. Enter a dark room quietly, turn on the light and watch where the roaches run. Spot treat these hiding places and known pathways, especially under and behind loose baseboards or molding strips and around pipes or conduits along the walls and through it. Do not treat entire floors, walls or ceilings.