The answer to 'cockroach nests' is that cockroaches typically do not build nests in the traditional sense. Instead, cockroaches will congregate in secluded, dark, and moist areas to form harborages or breeding sites. These areas can include cracks, crevices, under appliances, and within wall voids. Cockroaches prefer these hidden locations to lay their egg cases and for their young to develop.
Signs of a cockroach infestation can include seeing the insects themselves, finding their egg cases, or noticing droppings or other signs of their presence. If you suspect a cockroach problem, it's best to call a professional pest control technician, as they have the expertise and equipment to properly identify and eliminate the infestation. DIY methods may provide temporary relief but are unlikely to fully resolve a significant cockroach problem.