Cockroaches have an almost Transformer-like capability to scuttle, fly, walk upside down and flatten their crunchy bodies before disappearing into sliver-thin crevices. And unless they're hissing or have enough weight to make noise while they take a flagrant stroll across your paper or plastic goods, they are generally silent. Hard to kill? Yes, that too. All of these factors make them the most successful insect species in the United States, whether they belong to the half-inch or 2-inch (or longer) varieties.
Armies of these brown and black, six-legged, winged, long-antennaed and hardened crawlers are known to roam in moist basements and crawl spaces and in multi-unit dwellings in cities, not to mention in a few states known for them, including Texas and Florida, but where else do cockroaches hide out in the hundreds and millions when we don't see them?
One hint: If you see dead ones, no need to draw a little chalk line around their corpses; where you find them is a clue to their origin, route and destination. But if you see a live one that means there are likely whole cities of them hiding in your home.
Have the creepy-crawlies yet? Let's find out where these bacteria-carrying bottom-draggers hide.
While not quite a case of "the sky is falling!" many cockroaches like to hang out on ceilings in dark rooms and they can drop and flee in a second. Why they want to be out in a wide-open space, and upside-down, is a mystery, but if it's dark, they may be overhead.
Thankfully, most will scurry off into a less-conspicuous place once the lights come on or people approach. But unfortunately, if you're trying to catch a ceiling crawler it's difficult to knock them down without having them fall on top of you or to hit the ground running and disappear into an unreachable hiding place.
If you've seen cockroaches on the ceiling, it's likely they have cracks or areas of detailing such as crown molding to emerge from and return to in the daylight or well-lit hours.
As if their lacquered looking shells and wings aren't creepy-shiny enough, cockroaches really seem to enjoy getting wet and being around water. Areas where pipes come into a home, through walls, floors and backs of cabinets, are often ideally damp and continually releasing bits of warm condensation for roaches to get their bodies into. Exposed pipes on walls also provide good hiding places, as do areas around washers and dryers.
Insulating and taping off gaps between piping and walls or false-cupboard and cabinet backing can help keep these areas dry and less inviting. Some areas where pipes terminate with a faucet, such as in the bathtub, may be harder to control. And cockroaches have no problem climbing up into open faucets and making dramatic drops into tubs and sinks to say "Hi."
We love comfy furniture with just the right amount of firmness, softness and warmth, and so do cockroaches. Something about their flat, smooth bodies makes them prone to snuggling into tight spaces where they can feel fabrics or other materials on their topsides and undersides. They like our furniture so much that they may hunker down and lay their eggs there, leaving hardened colonies of eggs ready to hatch in weeks, producing from tens to thousands of young progeny. Yellowed and whitish egg casings might be under tables and chairs of wood and plastics too. If you're OK with mass destruction, egg casings are easy enough to remove and destroy.
Even when not laying eggs, cockroaches have been seen proudly wiggling their antennae at the top of the couch back until running away at first light. And take care especially when bringing new furnishings home: Inspect for pre-existing eggs or travelling critters.
Cardboard and Paper
Some varieties of cockroaches consider paper a delicacy or, on the opposite end, their preferred place for leaving waste. Envelope glue and just about any kind of paper attract roaches because of their smell and texture, and stacks of cardboard or food and beverage boxes are almost ideal places for hiding, eating and leaving trails of waste -- whether fecal matter or bacteria picked up on slender little feet and tacky underbellies.
Not only do cockroaches roll around in and feast on paper and cardboard products, they also destroy them with oils and acids that break down fibers and leave a really unpleasant smell. Keeping stacks of paper in tightly sealed cabinets and sorting rather than stacking mail in piles can help, as can disposing of cardboard outside of, but not too close to, the home as soon as boxes are emptied. Dusting recycling bins with a boric acid powder is not a bad idea either.
Yes, sadly, it's true; cockroaches spend time in our appliances both day and night. Stoves and refrigerators have nooks and crannies and in some cases warm, running motors that provide refuge during the sunlight hours and foraging at night. Water heaters are practically paradise because they provide a combination of water and warmth and are usually in areas hidden away from human traffic.
Small appliances on kitchen counters also attract cockroaches, and some favorite hangouts might be under or behind coffee makers, microwaves and blenders. And toasters, well, let's just say that shaking out more than the breadcrumbs is probably a good idea if you've seen any six-legged crawlers in your home.
Whether day or night, cockroaches aren't just hiding in the places mentioned in the kitchen; typically, they're all over the place because of the abundant moisture and food. Sinks and dishwashers or countertop dish draining mats are attractive to the bugs, as are any spots on floors, cabinets, appliance surfaces and furniture with traces of food particles.
Most of the time roaches will wait until nightfall or lights-out to race around in plain sight, but some of the bolder varieties will just run across your path in broad daylight. Those hiding in drawers are particularly bothersome because they deposit bacteria on silverware and cooking utensils. Treating these storage areas before filling them and again at regular intervals can control or eliminate the problem. Even mixing roach-killing powders in solutions used for washing floors and appliances will help considerably in most cases. It is important to use caution and keep any insecticide poisons away from your dishes and utensils, though.
As with kitchens, bathrooms provide a lot of moisture and plumbing cockroaches prefer. Unlike kitchens, however, bathrooms don't contain food, but they do have something else that roaches love: residues from soaps and grooming products, discarded paper tissues, and skin and hair sheddings. Yes, they are known to enjoy even hair and soiled toilet paper.
One good thing about the love of bathrooms and kitchens is that many cockroach species don't travel beyond these two rooms of the house. They have plenty to sustain them and keep out of bedrooms and upper floors in most cases. German cockroaches, the most common and prolific, however, go just about anywhere but also prefer sinks, bathtubs, areas around toilets and behind every possible surface containing water or traces of humidity.
In the case of bathrooms, pull out the big guns of treatment and traps and do it often. Sprays, by the way, are proven least effective, while powders and traps show better results.
Cupboards, Closets and Cabinets
Anyone who has ever pulled down an inhabited bowl or pan or found an unwanted treat in a cereal box knows that cockroaches are wont to roam throughout every inch of kitchen cabinets. They also cavort in closets and lay eggs in linen closets.
In particular, cockroaches like upper inside corners of cupboards and cabinets and hang upside-down there. Keeping all food in tightly-sealed containers is necessary if bugs of any kind are an issue, and not just for the squeamish factor, but also because roaches may carry food poisoning and other bacteria.
Thin dustings of boric acid-based powders and well-placed traps may help with areas where clothing and linens are stored, as well as in bathroom medicine cabinets and behind them.
Baseboards and Trim
Crown molding and historic wood baseboards are gorgeous and add a lot to an interior, but they also add a lot of places for cockroaches to hide. Maybe you thought your eyes were playing tricks on you or there was a small thread or hair hanging from decorative trim, but it could well have been an errant antenna from a large, crouching cockroach.
Thin, tight and dark areas beneath door and window trim, and at the base and corner crevices of walls are favorite spots for cockroaches, and most of us who have turned on the lights only to see running roaches have seem them scuttle along the wall and floor seams, disappearing into a space that's invisible to the naked eye. Checking all places where pieces of woodwork or trim and molding come together with walls and floors, and sealing up any cracks will leave cockroaches with fewer places to seek refuge.
Decor and Electronics
Seeing a fleeing cockroach from afar is bad enough, but often they're up close and personal and we don't know it until they emerge. They can jump out from behind books on shelves, from underneath or inside of electronics and light fixtures, and from on top of knick-knacks and candles. They like to blend in with decor, and unfortunately, these items are things we touch and dust and move around with our hands. Cockroaches like the backsides of mounted and freestanding picture frames and mirrors too, but we think, by now, you get the picture: They can hide almost anywhere!
Keeping areas as clean and clutter-free as possible goes a long way toward routing out the hiders though, and with persistence and prevention, they -- and their little eggs too -- can be eliminated.
What's in your typical can of bug spray? Find out how bug spray works at HowStuffWorks.
- Encyclopaedia Britannica. "Cockroach." Britannica.com. 2012. (June 28, 2012) http://www.britannica.com/EBchecked/topic/123709/cockroach
- Orkin, LLC. "Virtual Roach." Orkin.com. 2012. (July 1, 2012) http://www.orkin.com/cockroaches/virtual-roach/
- University of California Agriculture and Natural Resources Integrated Pest Management. "Cockroaches." IPM.UCDavis.edu. June 2007. (June 28, 2012) http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7467.html
- Williams, Harry E. "Control Cockroaches in the Home." UTExtension.Tennessee.edu. March 1994. (June 28, 2012) https://utextension.tennessee.edu/publications/Documents/pb1024.pdf