Cockroaches rarely cause structural damage. They can, however, contaminate food and spread disease by walking over, and excreting on, food or food preparation areas after having travelled through garbage and/or sewers. People with asthma may have a negative reaction to their droppings (feces) and body parts.
Cockroaches will live in any area where food, water, and shelter are available. They are attracted to buildings because of the warm, damp conditions offered by kitchens, bathrooms, basements, and plumbing areas. Their presence does not necessarily mean unclean conditions exist.
Roaches and their egg cases can hitch a ride into your home on various objects (including used furniture, food items, empty beer and soft drink bottles, and shipping cartons). Once inside a building, they travel quite easily. Because cockroaches are most active at night, they may go unnoticed for some time. Cockroaches are attracted to food sources that contain starches, sugars, and protein, but will eat almost anything when hungry.