Cockroaches, those resilient and unwelcome guests, have been household pests for centuries. Their presence can be both unsettling and unhygienic, spreading germs and bacteria, and triggering asthma and allergies. Understanding their dietary habits is vital for effective pest control, as their diet plays a significant role in their ability to thrive in our homes.
Cockroaches: Omnivorous and Opportunistic Eaters
Cockroaches, by nature, are omnivorous and opportunistic eaters. These insects exhibit an extensive dietary range and can consume just about anything organic, including plant and animal-based materials, as well as unconventional items like hair, fingernails, soap, toothpaste, book bindings, wallpaper glue, human waste, and even their own cast-off skins. Cockroaches are highly adaptive to the available food in their environment and are among the least selective eaters in the insect kingdom. Their wide-ranging diet means they can survive even when normal food sources are unavailable.
Instead of asking "what do cockroaches eat," it might be easier to answer a question about what they don't eat. Why? Because these scavengers are among the least picky eaters in the insect kingdom. Cockroaches have three elements working together to make them such voracious eaters. First, cockroaches are omnivores. This means they eat both plants and animals, they don’t care. Second, cockroaches are opportunistic eaters. They'll eat whatever you have in your home, as long as it also meets the third point: that the food be organic (i.e., not metal, plastic, etc.).
Dietary Preferences: A Roach's Favorite Foods
Cockroaches will devour most of the same foods humans enjoy, as humans are omnivores too, so it’s no surprise we share similar tastes. That's why you’ll find cockroaches in the kitchens, food storage, and prep areas of homes with infestations. Now, if your kitchen were a restaurant, cockroaches would definitely order certain types of foods before others. Sweets, starches, and animal proteins are a roach's favorite foods. They also like greasy food, cheese, or anything that's moldy or fermented. Take extra care to keep sugary foods in airtight containers, clean up your meat prep stations, and wipe down your counter for bread and any other crumbs left behind. Cleanliness is a vital part of cockroach prevention.
Sugary Foods and Why Roaches Love Them
These pests are known to have a sweet tooth and are particularly drawn to sugary substances.
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Starchy Foods: From Cardboard Boxes to Book Bindings
Starches like cardboard boxes and book bindings are susceptible to cockroach infestations.
Greasy Foods and Their Appeal
Cockroaches are also attracted to greasy, oily foods.
Human Food Items That Are Roach Magnets
These pests will feast on a wide range of human foods, from cereals to bread.
Unconventional Food Sources: When Roaches Get Creative
If your "restaurant" is "out" of their favorite food items, cockroaches won’t just head over to the take-out place down the block. They'll snoop around to see what else is on the menu, taking a taste of this and a bite of that along the way. Decaying matter gets their appetites going, so garbage and waste - even human waste - will serve as gourmet roach meals, as well as a few items in your home such as plants, soap, and makeup.
Despite being omnivores like us, cockroaches see many other items as viable food sources, ones we’d never imagine. For example, when you think of adding a starch element to a meal, potatoes, bread, or pasta come to mind. For cockroaches, the starch food group expands to include book bindings, paper, wallpaper paste, and the glue on the back of stamps. For protein, cockroaches view dead insects, animal skin (e.g., the soft inside of leather), and even human hair and fingernails as viable food sources. They’ll also eat their own young if food gets scarce enough. In fact, cockroaches have even been known to bite people, though it's extremely rare and only happens when the infestation has reached cataclysmic levels. Cockroaches are more likely to pick on calluses, eyelashes, dead skin flakes, and fingernails, rather than living tissue. This is because cockroach jaws are rather weak. Their sideways-moving mandibles are great for carrying and chewing morsels of the typical cockroach diet, but these same jaws would have a hard time puncturing your skin. They have an easier time with keratin, a protein found in your nails and hair.
Read also: The Hoxsey Diet
Survival Without Food: How Long Can Roaches Last?
It's rare that such an expedient scavenger like the cockroach would ever run out of food. Outdoors, cockroaches might eat decaying plants and dead wood. In sewers, they make the most out of the waste, sewage, and water, especially since many species of cockroach thrive in moist, dark places.
But even then, it’s not unheard of for a cockroach to be unable to find food, especially if the infestation has outgrown its resources. So, what do roaches eat if there's nothing around? Actually, nothing. Many species of cockroach can live up to a month without eating, though only if they have water. That's the type of enemy you're dealing with. Even if you put down roach traps and bait, even if you clean your home, that might not be enough to stop the roaches who are waiting just outside - or inside - your walls. You can't starve them out. Only a pest management professional that can stand behind their guarantee and relentlessly protect your home will give you the ultimate advantage.
Cockroaches are incredibly resilient creatures, capable of surviving extended periods without food. Their remarkable adaptability includes the ability to enter a state of dormancy when resources are scarce. While cockroaches can survive without food for a while, they require water more frequently.
The Importance of Water
While their diet is broadly varied, American cockroaches can survive for months without feeding but can only survive around a month without hydration. Similarly, German cockroaches can last about 42 days without food, but they’re only able to endure approximately 12 days without water. Most cockroach species can manage for extended periods without food, but a consistent water supply is crucial for their survival.
Species-Specific Diets: A Closer Look
Different cockroach species have unique dietary preferences.
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German Cockroaches
The German cockroach is a species notorious for its adaptability to indoor environments, particularly within homes. These cockroaches are typically found in areas that are warm, humid, and close to food sources like kitchens, dining rooms, and bathrooms. As nocturnal scavengers, they are known to crawl through these spaces in search of food scraps, demonstrating the ability to penetrate paper and access food not stored in airtight containers.
The German cockroach's diet is extensive and encompasses a variety of items that you may find in a typical household. They have been observed to consume desserts, meats, and fruits, along with more unorthodox foods such as feces and mouse droppings. Furthermore, any food products left out overnight are potential targets. Therefore, properly securing these preferred food sources can be a significant step towards controlling a German cockroach infestation.
German cockroaches are among the most common and troublesome species. They prefer warm, humid environments and are often found in kitchens and bathrooms. Their diet includes a wide range of organic materials, from food scraps and grease, to glue, hair, and other debris, making them highly adaptable. These cockroaches typically live inside only, and can be brought into the home in boxes, groceries, or shared walls.
American Cockroaches
American Cockroaches, one of the most common cockroach species globally, are notable for their larger size and their ability to fly. Unlike German Cockroaches, they are typically found outdoors in dark, warm, and damp places like sewers or basement drains. However, they can also invade homes, particularly during hot or dry outdoor conditions. Interestingly, they also show a particular fondness for fermenting or rotting foods, which can often lead them to congregate around garbage cans or compost heaps. Given their wide dietary range and potential to spread disease and contaminate food, it's vital to address any American cockroach infestations promptly.
American cockroaches, or palmetto bugs, are larger and often found in the sewer, trees, plants, and soil. They prefer decaying organic matter but are not picky eaters. Their diet can include food scraps, pet food, and even paper and fabric if they have food, oil, or grease stains. American cockroaches can damage clothing and materials as they search for food and commonly invade after a heavy rain.
Australian Cockroaches
Australian cockroaches are similar in size to American cockroaches but are more commonly found outdoors. They feed on a variety of plant materials and decaying organic matter. However, they can enter homes in search of food, feeding on crumbs, food spills, and even pet food.
Wood Roaches
Wood roaches, contrary to some other cockroach species, primarily have a diet based on decaying organic matter and are not generally drawn to human food sources. This makes them less likely to infest indoor spaces like kitchens. Given their preference for decaying organic materials, environments with ample old wood or leaf piles can potentially attract wood roaches. Therefore, maintaining cleanliness by removing such piles around the house can be an effective preventative measure against wood roach infestations.
Where Cockroaches Find Food: Common Hotspots
Cockroaches can source food from various places within the home due to their excellent scavenging abilities. The kitchen is one of the primary areas where cockroaches can find food. Floors, especially carpets, are also common areas that provide ample food sources for cockroaches as they often collect crumbs. Roaches are usually crawling around on the ground seeking out even the tiniest food particles with their strong sense of smell.
Pet food is another potential source of nourishment for these pests, as its composition is close enough to human food from a cockroach's perspective. Cockroaches are likely to consume leftover pet food, crumbs, or residue that might be left in pet bowls.
Health Risks Associated with Cockroach Diet
Cockroaches pose a significant threat to human food, mainly due to their preference for scavenging in unhygienic locations. From sewers to litter boxes, cockroaches can transfer harmful pathogens to our food and cooking surfaces merely by traversing them. This ability can result in various health complications, such as food poisoning, diarrhea, and dysentery, among others.
Moreover, since cockroaches also demonstrate a fondness for fermented and decaying materials, this makes them vectors for disease and bacteria.
Cockroaches are linked with allergic reactions in humans. One of the proteins that trigger allergic reactions is tropomyosin, which can cause cross-reactive allergy to dust mites and shrimp. These allergens are also linked with asthma.
How Cockroaches Eat and Digest: A Biological Perspective
Cockroaches employ their rudimentary mandibulate mouthparts to bite and chew their food. Their mouthparts' structure allows them to break down various materials including thin plastic and paper, a capability not shared by pests like bed bugs or mosquitoes that have piercing and sucking mouthparts. Common city-dwelling species such as the German, Oriental, and American cockroaches can all exhibit this behavior.
Cockroaches boast a complex digestive system that hosts symbiotic bacteria. These bacteria assist the cockroach by breaking down and metabolizing a wide variety of substances including harmful compounds and cellulose, a component found in plant materials and various man-made objects. The ability to digest cellulose grants cockroaches a dietary advantage and allows them to consume and gain nutrition from organic materials like paper, cardboard, book bindings, and plant debris. This ability is not shared with many other animals and insects outside of termites and a few other insects. This metabolic versatility is largely credited to the cockroach's evolutionary journey spanning millions of years, during which they have adapted to survive in harsh conditions and consume a wide variety of substances. This remarkable dietary resilience has been verified by scientific studies, including one that found a significant part of the American cockroach's genome is dedicated to metabolizing toxic or dangerous materials.
Preventing Infestations: Limiting Food Sources
Understanding what cockroaches like to eat and what attracts them to your home is essential for maintaining a pest-free living environment. Eliminating cockroach food sources is a key strategy in pest control, as it makes your home unappealing to these insects. Here are some key steps to take:
- Store food properly: Keep all food items in air-tight containers. This includes leftovers and open foods. This reduces the availability of easy food sources for cockroaches.
- Clean your environment: Wipe up spills immediately and maintain a clean kitchen. Regular cleaning, especially in food preparation areas, is critical. This should extend to a regular sweep, mop, and vacuum routine for all floors to remove any potential food particles.
- Manage waste effectively: Empty your garbage on a regular basis and rinse cans, bottles, and plastics before putting them in recycling bins. Food waste and residues on recyclables can attract cockroaches.
- Restrict eating areas: Avoid eating outside of your kitchen or dining room to limit potential food spillage that could attract cockroaches in other areas of your home.
- Clean pet bowls: Empty your pet's water and food bowl regularly to prevent cockroaches from finding an easy meal.
- Maintenance of appliances: Deep clean your cooking appliances (stove, oven, refrigerator) daily, focusing on any narrowed gaps from grease and spilled food.
- Manage outdoor spaces: Protect your home's perimeter from bugs and other pests by ensuring there’s a 3-foot gap from plants and other foliage to your home's perimeter.
- Address Infestations: If your home is already infested, consider calling a pest control company to address the situation.
Ensure dirty dishes are promptly washed, and pet food is not left out overnight.
Cockroaches in the Wild vs. Home
Homeowners may unknowingly create ideal conditions for an infestation by leaving food sources readily available. In the wild, cockroaches primarily consume organic matter like leaves, wood, and decomposing plant material. These insects play a crucial role as scavengers in ecosystems. They help break down decaying matter and recycle nutrients. Cockroaches are not picky eaters. They will feast on food crumbs, leftovers, and even dead insects they come across in our homes.
Cockroach Control: A Multifaceted Approach
Preventing and controlling cockroach infestations requires a comprehensive approach. Maintaining a clean home with good sanitation practices is essential. However, even the best preventive measures may not be enough.
Even if you put down roach traps and bait, even if you clean your home, that might not be enough to stop the roaches who are waiting just outside - or inside - your walls. You can't starve them out.
For those wondering how to get rid of cockroaches, consider humane pest control methods that do not harm the environment, such as EarthKind’s Stay Away Ants & Cockroaches. Choosing eco-friendly solutions to use around the home prevents accidental poisoning of pets and unintended animals. For a naturally smarter pest control solution, try EarthKind’s Stay Away Ants & Cockroaches deterrent pouches. To find a store near you, visit the Store Locator.
Household chemicals like sodium bicarbonate (baking soda) have been suggested, without evidence for their effectiveness. Garden herbs including bay, catnip, mint, cucumber, and garlic have been proposed as repellents. Poisoned bait containing hydramethylnon or fipronil, and boric acid powder is effective on adults. Baits with egg killers are also quite effective at reducing the cockroach population. Alternatively, insecticides containing deltamethrin or pyrethrin are very effective. In Singapore and Malaysia, taxi drivers use pandan leaves to repel cockroaches in their vehicles. Natural methods of cockroach control have been advanced by several published studies especially by Metarhizium robertsii (syn. Some parasites and predators are effective for biological control of cockroaches. Parasitoidal wasps such as Ampulex wasps sting nerve ganglia in the cockroach's thorax, causing temporary paralysis and allowing the wasp to deliver an incapacitating sting into the cockroach's brain. Cockroaches can be trapped in a deep, smooth-walled jar baited with food inside, placed so that cockroaches can reach the opening, for example with a ramp of card or twigs on the outside. An inch or so of water or stale beer (by its odor) in the jar can be used to drown the insects.
Dubia Roaches and Their Diet in Captivity
People often ask what to feed Dubia roaches. Diet, along with environment, is one of the most impactful and complex decisions roach-keepers make. To thrive, Dubia need the usual tropical roach accommodations: proper heat, humidity, and darkness. These elements are straightforward-roaches either have them, or they don’t.
Nutrition, however, stands apart from these basic needs. While ensuring Dubia roaches have the foods and substances necessary to grow and thrive, meeting their nutritional requirements is much more complex than simply adjusting heat, humidity, or darkness. To start, there are many dietary options, and just as many ways for things to go wrong as right. The dietary decisions you make matter: What you feed your Dubia can mean the difference between healthy and unhealthy, productive and unproductive, or even alive and dead.
Like most cockroaches, Dubia can survive on a range of food and food-like substances. They are generalist feeders. There are even reports suggesting they can survive on paper and cardboard glue. However, how long and how well they can live eating such things is an open question. Dubia roaches evolved eating plant matter in various stages of decay, fungi, and probably dead insects and small animal carcasses they stumbled upon. Their “natural” diet probably varies a lot in the wild.
In captivity, people feed their Dubia many foods. On one end of the spectrum are highly processed substances like dog food, cat food, cereal, fish flakes, etc. Sometimes people “dust” these foods with vitamin or mineral powders (like vitamin A or calcium) before offering them up to their roaches. On the other end of the spectrum, you have fresh, raw foods like those found in the supermarket produce aisle.
A Week in the Diet of Dubia Roaches: A Food Diary
Here’s a glimpse into a typical dietary week for Dubia roaches:
- Monday: Bananas (ripe bananas make great Dubia food)
- Tuesday: Potatoes (particularly sweet potatoes)
- Wednesday: Beets & Carrots
- Thursday: Apples (peeled and cored to avoid pesticide exposure)
- Friday: Super Secret Roach Chow (a carefully researched and developed blend)
- Saturday: Fasting (skipping feedings can be beneficial)
- Sunday: Oranges and Greens (tangerines and mixed greens)