Do exterminators have to spray the whole house?

No, exterminators do not have to spray the whole house in most cases and often use targeted treatments rather than blanket spraying, though the extent of treatment depends on pest type, infestation severity, and home layout. For common pests like ants, cockroaches, spiders, and occasional invaders, modern integrated pest management emphasizes targeted application, so technicians apply gel baits in cracks and crevices behind appliances and under sinks for cockroaches and ants, residual sprays along baseboards, entry points, and exterior foundation, and dusts in wall voids, rather than spraying every room and surface. For bed bugs, treatment is focused on bedrooms, including mattress seams, box springs, bed frames, baseboards, and nearby furniture, not necessarily the whole house unless infestation has spread. For rodents, exterminators set traps along walls and in attics and seal entry points rather than spraying. For termites, treatment is focused on foundation, soil, and infested wood. For German cockroaches in kitchens, spraying is concentrated in the kitchen and bathrooms where they live. Whole-house spraying is typically only done for severe infestations, for flea treatments where all carpets need treatment, or for preventative quarterly barrier sprays where exterior foundation and interior entry points are treated. Professional companies avoid unnecessary spraying to reduce chemical exposure, protect children and pets, and follow label directions. They will explain what areas will be treated and may ask you to vacate treated rooms for 30 minutes to two hours until dry. Targeted treatment is more effective and safer than spraying everywhere.