- The standard method of treating for cockroaches has been to spray insecticides on baseboards and in cupboards, with the hope that cockroaches will crawl across the band of dried insecticide and the residue left from the application will kill them. We now know this type of treatment is not very effective. Reasons why include:
- Cockroaches do not live behind baseboards, but live in dark, damp locations near food and water sources. Efforts to locate and treat these hiding places are much more effective.
- Insecticides are not 100 percent effective and, unless efforts are made to reduce food, water and harborage, populations of the prolific German cockroach are likely to rebound.
- Cockroaches species, including the German cockroach, have developed insecticidal resistance to the many insecticides.
- Most insecticidal sprays, especially aerosol treatments, don't have much residual activity.