To crack down on roaches, here are some suggestions from "Insect and Rodent Control Through Environmental Management: A Community Program" published by the World Health Organization (WHO):
Avoid dampness within the house, especially in the kitchen and near water pipes and sinks. Repair leaking faucets, make sure the drainage is working, and avoid spilling water. Keep the house clean and tidy. Clothes and other household articles should not be kept on the floor. Store food in close containers or keep it inside closed cupboards. Household refuse should be placed in closed containers and disposed of properly.
Improvements inside the house can eliminate the hiding places of roaches. Plug cracks and crevices in walls and floors.
Keep yards and vacant lots clean. Articles which are no longer used should not he placed there. Make adequate arrangements for both liquid and solid waste disposal in the community.