Things You'll Need
Boric acid insecticidal dust
Most species of cockroach originated from tropical or sub-tropical areas. As such, they like warm areas like the motor compartments of refrigerators. They also like dark, humid areas with clutter and grime, although they also infest sanitary areas. Cockroaches feed on a large variety of materials, including meat, sweets, leather, book binding and wallpaper paste. They contaminate food with their excrement and saliva. They also leave an unpleasant odor and carry diseases. Several methods can help you make your refrigerator an unattractive place for cockroaches.
Inspect the area in and around your refrigerator for cockroaches. Observe their characteristics and identify the type of cockroaches that infest your refrigerator. Proper identification can help you use their behavioral patterns to remove them. Contact your local Extension office if you need help determining the species.
Clean the areas beneath and behind the refrigerator to prevent food particles from building up. Look for egg cases attached to the surface of your refrigerator motor, then remove and destroy them. Empty the pan that collects condensed water underneath your refrigerator. Use garbage bins with tight-fitting lids and take out the garbage as frequently as possible. Keep paper, cardboard and debris away from refrigerators because cockroaches can hide in them.
Seal any cracks measuring 1/8 inch or larger in the foundation and exterior walls of your home. Caulk any openings around the electrical outlets for the refrigerator.
Apply a light, even layer of insecticidal dust under and around the refrigerator. Insecticidal dust can enter crevices and work well to reach cockroaches hiding in refrigerators. It usually contains boric acid, which sticks to cockroach bodies, becomes ingested when they groom themselves and eventually kills them. Boric acid dust takes seven days or more to reduce cockroach popoulation.
Place cockroach traps in areas that cockroaches frequent, based on your observation and the habits and preferences of the cockroach species. These traps usually have a sticky surface to immobilize cockroaches. Check the traps every day to monitor the progress of the treatment. When you have successfully removed the cockroaches, you will no longer catch any in your traps.
If boric acid dust becomes wet, dries and cakes, it loses its effectiveness. Reapply the dust to areas where this occurs.
Don't use boric acid outside because it could poison plants.
Edriaan Koening began writing professionally in 2005, while studying toward her Bachelor of Arts in media and communications at the University of Melbourne. She has since written for several magazines and websites. Koening also holds a Master of Commerce in funds management and accounting from the University of New South Wales.