In addition to food and moisture, cockroaches require a place to live. The cockroach harborage is critical to its survival. Cockroaches prefer dark places that are warm and moist. Places that provide tight spaces such as stacks of newspaper or cardboard, piles of clothing, or cracks and crevices in structures are ideal.
Eliminate harborages by doing the following:
• Seal cracks and crevices. Adult cockroaches can fit into cracks only about 1/16 inch and prefer spaces of about 3/8 inch.
• Keep clutter such as newspapers, bags, and clothing from accumulating.
• Stack firewood off the ground and well away from the house.
• Pull mulch away from the house. The large, outdoor cockroaches breed prolifically in pine straw mulch and poorly in gravel or on bare soil.
• Keep shrubbery and ornamentals well trimmed and away from the house. Ivy is a favorite breeding place for outdoor cockroaches.
• Remove all dead palm branches. Palm bracts are prime harborage for outdoor cockroaches.
