The short answer is yes, cockroaches can reappear after extermination even after professional treatment. Eradicating cockroaches is just one part of an effective pest control plan. It's normal for cockroaches to come out once sprayed, and for two weeks, you'll see a lot of them, but don't be afraid. It is typical to see them wandering around since they have been sprayed to look for sources of food or water so that they can thrive.
We know how creepy cockroaches can be, but you have to deal with that when you're treated at home because it's inevitable to see them after spraying. It's normal to see some cockroaches weeks after treatment, regardless of how effective the treatment is. Some cockroaches survive spraying with pesticides for a few more days after spraying. One of the worst problems homeowners can face are cockroaches, and they can be truly tenacious.
You can spray, set up bait stations and clean thoroughly, only to find that cockroaches keep coming back for more. Fortunately, there are ways to combat your cockroach problem if you understand what causes them. After all, if you detect one, there are likely to be more, which may indicate an ongoing infestation, so professional cockroach control services are required to prevent and eliminate it. However, you shouldn't take success for granted either: if there are a significant number of cockroaches left in the treated areas around your property (which means there are no significant changes), contact your pest control professional for an appropriate estimate and expectations.
One strategy is for the pest control professional to partner with the owner to reduce the attraction of cockroaches. After professional cockroach pest control services treat your home, you'll see a reduction in the number of cockroaches, their nesting materials, and typical signs of infestation. If the pesticide is highly effective, cockroaches will start to come out after a few hours or days due to the negative effect of chemicals. Even though your house is sprayed or treated by exterminators, you still need to keep checking for cockroaches, as this will give you an idea of whether pest control worked or not.
Depending on the infestation, it can take months for professional pest technicians to fully control the cockroach problem (this is usually the case with German cockroaches). According to the Economic Entomology Journal, insecticides containing diazinon and bendiocarb as active ingredients were not effective in controlling cockroach infestation. With this in mind, you should research whether the cockroaches are dead or if you need to use a different pesticide. Pest control treatments for cockroaches usually take a long time to work and don't always kill them directly; some cockroaches survive, but they're likely to find the quickest way out of your property.
When you find cockroaches even after a considerable number of days, you should inform the same professional pest control company. Pest control professionals can also use traps, such as sticky boards, in areas where cockroaches can travel or hide. Because of this, general treatment is also not always sufficient to kill cockroach eggs, and may require professional pest control services. This is because their pest company has sprayed their normal hiding places with pesticides, making them inhospitable to cockroaches.