Most people assume cockroaches enter homes looking for food. But water is actually the primary attractant — cockroaches can survive a month without food but only a week without water. A single dripping faucet provides enough moisture to sustain a colony indefinitely. Understanding the hierarchy of attractants reveals why some homes get cockroaches and others don't.
Dripping faucets, condensation on pipes, leaking dishwasher seals, pet water bowls left overnight, and wet mops or sponges stored under the sink. The kitchen sink and bathroom are the two rooms where cockroaches are most commonly found — both are the rooms with the most water access. Fix every drip, wipe down sinks before bed, and don't leave standing water overnight.
German cockroaches prefer temperatures between 70–85°F — which is exactly indoor room temperature. They cluster behind refrigerators (compressor heat), inside dishwasher motor housings, behind ovens, near hot water heaters, and around electronics that generate warmth. You can't change your home's temperature to deter them, but knowing where they cluster guides bait placement.
Cockroaches eat almost anything organic — crumbs, grease, soap residue, paper, cardboard, pet food, and even glue in book bindings. The kitchen provides the most concentrated food sources: grease behind the stove, crumbs under the toaster, pet food left in bowls, food residue in garbage disposals, and unsealed pantry items. Deep-clean behind appliances quarterly and store all food in sealed containers.
Cockroaches are thigmotactic — they prefer touching surfaces on multiple sides of their body simultaneously. This is why they squeeze into cracks, crevices, hinges, and the tightest gaps behind and under appliances. This behavior is also why gel bait placed in cracks is so effective — it puts the toxicant exactly where cockroaches prefer to be.
German cockroaches are almost always introduced — they arrive via grocery bags, delivery boxes, used appliances, and shared laundry facilities. They don't come from outside. American cockroaches (palmetto bugs) enter from sewers through floor drains and pipe penetrations. Oriental cockroaches enter through foundation cracks at ground level.
Prevention by species: For German cockroaches, inspect incoming items. For American cockroaches, ensure all floor drains have water-filled P-traps and seal pipe penetrations. For Oriental cockroaches, seal foundation cracks and reduce exterior moisture.