Nothing is worse than finding an infestation of bugs in your home. But unlike insects such as spiders, cockroaches tend to go unnoticed. Unless you have a large population of them, it's not likely that you'll see them out and about. "The most common way people realize they have an issue is by seeing the actual insects themselves, but there are other indications that roaches have taken up residence in a structure," says James Agardy, ACE, technical and training manager at Viking Pest Control. And once you identify these sneaky signs of roaches, you'll want to call an exterminator right away. Keep reading to find out all the roach tells and to make sure your home stays pest-free.
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1 | An oily, musty smell.
Shutterstock/IrinaK"If you’ve ever stepped into a cockroach-infested attic or a basement, you may have noticed a musty and unpleasant odor. This mixture of food scraps, dead bugs, and other organic matter is what roaches leave behind as they roam your house," says pest expert Jordan Foster.
Foster goes on to explain that roaches use "chemical messages," which include their scent, to communicate with each other.
Molly Keck, integrated pest management program specialist and board-certified entomologist at Texas A&M AgriLife Extension Service, adds that cockroaches usually like humid, dark places, so they'll nest under sinks, behind refrigerators and dishwashers, and wherever food is found. Their most common spots are the bathroom, kitchen, or laundry room, so if you notice strange smells coming from these rooms, it might be roaches.
2 | Reddish-brown marks
ShutterstockCockroaches tend to congregate in areas near water, like your bathroom or kitchen sink—and they'll usually leave behind a trail of evidence.
"Cockroaches that live in areas with high humidity usually produce dark matter and smear it as they crawl," says professional pest control specialist and entomologist Nicholas Martin. He notes that the marks are usually found on horizontal surfaces.
"Roaches secrete a pheromone that leaves behind a starchy residue," adds Lorne Hanewich, corporate trainer at Clarks Pest. You should look for brownish streaks or smears along walls and surfaces. These will often show up in the kitchen as roaches are searching for food sources.
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3 | Droppings
iStock"Roaches are very good at playing hide and seek," says Martin. "However, they can’t hide their feces."
Smaller cockroaches produce droppings that look similar to ground pepper, while the adults leave cylindrical feces, Martin explains. He warns that even a sparse amount of droppings could be a sign of a large infestation.
Hanwich points out that fecal matter can also look like coffee grounds. "Check for these in hidden areas like kitchen cabinets, drawers, and behind appliances," she tells Best Life.
Often, the droppings will be on both horizontal and vertical surfaces, as well as areas where two surfaces meet like countertops and cabinets.
4 | Egg cases
ShutterstockCockroach egg sac cases are often found in the nooks and crannies of your kitchen, but Martin says you're unlikely to spot these cases (which are only about a quarter-of-an-inch long) if you don't know where to look for them.
According to Prevention, the eggs are often laid "in a sheltered location like the cracks and crevices in your kitchen or bathroom where they typically live."
Jim McHale, president of JP McHale Pest Management, notes that a single case can contain 20-40 eggs and hatch within a month, so it's important to act quickly and destroy any egg cases you find.
5 | Chew marks
ShutterstockCockroaches will nibble on almost anything. Large infestations can leave behind chew marks on a variety of items in your pantry, including food packaging, Martin says.
Georgios Likopoulos, pest control expert at Fantastic Services, adds that they're attracted to the warmth and food residues around kitchen appliances. He advises sealing any cracks or openings near these appliances and making sure that any food is stored in airtight containers.
6 | Shed exoskeletons
Dr Morley Read/ShutterstockLike snakes, cockroaches shed their skin. They do this because their exoskeletons don't grow with them. "As the roaches grow, they will molt their exoskeletons and sometimes these cast skins will be observed as well," says Agardy.
The casing is typically white or clear, looks like a deflated cockroach, and is a bit larger than the egg casings. Hanewich says that finding these translucent, shell-like remnants can indicate an infestation.
However, be aware that cockroaches will often hide their exoskeletons. "They are nocturnal and prefer dark, warm, and secluded environments," says Likopoulos, so check any areas with pipes, small openings, or food and water remnants.
7 | Unusual pet behavior.
ShutterstockIt's always important to pay attention to your pet's behavior, which can even help uncover a roach infestation.
Animals have a strong sense of smell and might be sniffing a lot more than normal if cockroaches are present. "Cats and dogs may become unusually interested in certain areas if they sense cockroach activity," says Hanewich.
Roaches are also attracted to pet food, so it's important to be extra mindful of the area where they eat as well as where the food is stored.
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