Usually the first sign there are cockroaches present is… seeing a cockroach! Otherwise, you might not even think about a roach nest being in your home. Other signs include dead roaches or old, molted exoskeletons, roach droppings (which looks like black pepper) and the musty odor roaches tend to produce. Keep a close eye on any signs you see to find out the size and location of any infestation you could be dealing with.