What are the key indicators of a cockroach infestation?

The surest indicator of a roach infestation is the sighting of live specimens, especially during the daytime. Other warning signs are strong oily or musty odors, an abundance of coffee-like or cylindrical droppings near food or water sources, and the presence of egg cases behind furniture or in books.

You may also notice brown smear marks on horizontal surfaces, such as counters and baseboards, or damage to food packaging and organic goods, such as leather and book paper. The German cockroach loves humidity and is most likely to be found in bathrooms and kitchens, while the Oriental variety likes basements and drains.