Cockroaches are undoubtedly one of the most hardy insects on the planet and can be found infesting everything from your home to restaurants or inside a cardboard box. They can fit through cracks allowing them to travel along water pipes and electrical lines from room to room and even one apartment to the next.
German cockroaches usually gain entry to a building by riding in boxes, stashing in furniture or hitchhiking on other items brought into the home. Other species typically invade from the outside, sneaking in through cracks and crevices.
German cockroaches fecal matter contains a pheromone indicating to other cockroaches that the area is a suitable place to harbor. Since most cockroaches prefer to rest on wood rather than other surfaces, you will often find them in wooden cabinets or cardboard boxes. Aggregation points form when large numbers of cockroaches congregate and fecal matter has accumulated.
cockroaches are extremely difficult to get rid of which is why professional treatment is nearly always required. Having a clean environment devoid of a food supply may help temporarily but is hardly ever enough to remove an infestation.