What Do Cockroaches Eat? Their Surprising Diet Explained

What Do Cockroaches Eat?

Cockroaches are among the least picky eaters in the animal kingdom. As omnivorous scavengers, they will consume almost any organic material available to them. This dietary flexibility is one of the reasons they have survived for over 300 million years and thrive in human environments where food sources are abundant.

Understanding what cockroaches eat is essential for effective prevention and control. When you know what sustains them, you can systematically cut off their food supply. For more on cockroach biology and control, see our complete guide to cockroaches.

Preferred Foods

Cockroaches have clear food preferences, even though they can eat almost anything:

Starches and Sugars

Starchy and sugary foods are cockroach favorites. They are attracted to bread, cereal, pasta, cookies, fruit, and anything with sugar. Even small amounts of spilled sugar or flour can sustain cockroaches for extended periods.

Grease and Fat

Cockroaches love grease. Stovetop grease splatters, range hood buildup, and greasy residue behind appliances are powerful cockroach attractants. This is one reason kitchens are cockroach hotspots.

Meat and Protein

Animal proteins including meat scraps, cheese, and pet food are highly attractive to cockroaches. Uncovered pet food bowls left out overnight are a common contributor to infestations.

Decaying Organic Matter

Many species, particularly American cockroaches and Oriental cockroaches, feed on decaying plant material, compost, and sewage.

Surprising Things Cockroaches Eat

When preferred foods are unavailable, cockroaches turn to some unexpected food sources:

Paper and Cardboard

Cockroaches eat paper, cardboard, newspaper, and book bindings. They can digest cellulose with the help of bacteria and protozoa in their digestive systems. Cluttered storage areas with cardboard boxes provide both food and shelter.

Glue and Adhesives

The starch-based glue used in book bindings, wallpaper paste, postage stamps, and envelope flaps is nutritious to cockroaches.

Soap

Bar soap contains fats and oils that cockroaches find appealing. Finding nibble marks on bar soap in your bathroom is a sign of cockroach activity.

Hair and Dead Skin

Human hair, fingernail clippings, and dead skin cells contain enough protein and keratin to sustain cockroaches. This is one reason they may be found in bathrooms and bedrooms.

Leather

Cockroaches can eat leather products including shoes, belts, and book covers.

Other Cockroaches

Cockroaches will resort to cannibalism when food is scarce, eating dead or weakened members of their own species. This behavior actually helps spread bait products through a colony, as cockroaches that eat poisoned individuals also receive a lethal dose.

What Cockroaches Cannot Eat

Despite their broad diet, cockroaches cannot eat:

• Inorganic materials like metal, plastic, and glass
• Intact synthetic fabrics (though they may eat stains on fabric)
• Fresh wood (unlike termites)

How Long Can Cockroaches Go Without Food?

Cockroaches can survive remarkably long without food, though the exact duration depends on the species and environmental conditions:

• German cockroaches: About one month without food
• American cockroaches: About one month without food
• Most species can survive much longer without food than without water

This ability to go extended periods without food means that even thorough cleaning may not starve them out quickly. Treatment with baits and other methods is necessary alongside sanitation.

Cutting Off the Food Supply

While eliminating every potential food source is impossible since cockroaches eat so many things, reducing food availability puts stress on the population and makes baits more attractive:

Kitchen Hygiene

• Store all food in sealed glass or hard plastic containers
• Wipe down countertops and stovetops every evening
• Clean grease from behind and under appliances regularly
• Sweep or vacuum floors daily
• Clean inside toasters, microwaves, and other small appliances

General Sanitation

• Take out garbage daily and use bins with tight-fitting lids
• Store pet food in sealed containers and remove bowls at night
• Clean up spilled birdseed around feeders
• Reduce clutter, especially cardboard boxes
• Vacuum regularly to remove hair, skin flakes, and crumbs

Bathroom Practices

• Wipe down sinks and tubs
• Remove bar soap when possible or use liquid soap
• Clean hair from drains and floors
• Empty bathroom trash regularly

For comprehensive prevention strategies, see our guide to cockroach prevention tips and how to get rid of cockroaches.

Expert Sources and References

• EPA - Sanitation for Pest Prevention - Federal guidance on food management practices that reduce cockroach attractants
• University of Florida Entomology - Cockroach Feeding Behavior - Research on cockroach dietary preferences and feeding ecology
• National Pest Management Association - Professional resources on understanding cockroach food sources for effective control
• Purdue Extension Entomology - Extension research on cockroach nutrition and its implications for bait development

Professional Insight: Using Diet Knowledge for Better Bait Acceptance

In 15 years of IPM work, understanding what cockroaches eat has directly improved my bait placement success. During a treatment in a restaurant in Nashville, Tennessee, in the spring of 2022, the initial gel bait placement showed poor acceptance because the kitchen had abundant grease and food waste competing with the bait. I worked with the kitchen manager to implement a deep-cleaning protocol targeting grease buildup behind the fryer and under prep tables. Once the competing food sources were reduced, the cockroaches consumed the bait readily and the population declined rapidly.

I also use cockroach dietary habits to identify non-obvious food sources that sustain infestations. In an office building in Richmond, Virginia, in the winter of 2021, German cockroaches were thriving despite no kitchen being present. My inspection revealed that employees were leaving food crumbs in desk drawers, coffee rings on desks, and snack wrappers in open trash cans. These seemingly minor food sources were sufficient to sustain a moderate cockroach population. Implementing sealed trash cans and a clean-desk policy, combined with bait treatment, eliminated the problem. -- Sarah Mitchell, BCE, IPM Specialist

Main Causes

Cockroaches are drawn into and sustained within homes by the diversity of food sources available in human environments. Kitchens present the strongest concentration of attractants: grease behind appliances, crumbs in appliance gaskets and cabinet crevices, open or loosely sealed pantry goods, and pet food left out overnight. Bathrooms offer a second tier of organic material in the form of soap, hair, skin cells, and paper residue near toilets and waste bins. Living areas with cardboard storage, newspapers, and clutter provide both food and shelter in the same location, particularly through the starch-based adhesives in cardboard and paper products. Restaurants, offices, and any space where food is prepared or consumed regularly create conditions that sustain large cockroach populations even with daily cleaning, because microscopic food residues accumulate in cracks and gaps faster than routine sanitation removes them. In multi-unit buildings, the combined food waste of many households creates an environment rich enough to support year-round breeding populations across shared infrastructure.

How to Identify

Signs that cockroaches are actively feeding in your home include droppings near food storage areas, chew marks or damage on food packaging, nibble marks on bar soap, and shed skins near pantry items. German cockroach droppings resemble coffee grounds or black pepper and accumulate at the back of cabinet shelves, inside drawer tracks, and around appliance gaps. American cockroach droppings are larger, cylindrical, and often found near drains and garbage areas. A musty or oily odor in closed cabinets or behind large appliances indicates a population feeding and living in those areas. Damage to book bindings, cardboard boxes with irregular chewed edges, and gnawed labels on food packaging are all active feeding signs. Sticky traps placed overnight in the kitchen reveal which food storage or preparation zones cockroaches are actively foraging in, based on where the most captures occur.

Prevention

Cutting off cockroach food sources is the most sustainable prevention measure available. Store all pantry goods in hard-sided sealed glass or plastic containers since cockroaches can chew through thin plastic bags and cardboard. Wipe down stovetops and countertops every evening and clean grease from behind appliances regularly, since grease buildup is one of the strongest cockroach attractants in a kitchen. Pick up pet food bowls at night and store pet food in sealed containers. Take kitchen garbage out daily and use bins with tight-fitting lids. Switch from bar soap to liquid soap dispensers to eliminate one bathroom food source cockroaches exploit. Vacuum floors, baseboards, and behind furniture regularly to remove the hair, dead skin, and organic dust that sustains cockroaches in rooms without obvious food sources. Break down cardboard boxes promptly and avoid storing large amounts of paper-based materials in enclosed spaces where cockroaches can feed undisturbed.

Risk and Severity

Cockroaches are significant public health pests. Cockroach allergens — proteins shed in feces, saliva, and decomposing bodies — are documented triggers for asthma attacks and allergic rhinitis, particularly in children, and the CDC identifies cockroach allergen exposure as a major contributor to pediatric asthma in urban housing. Mechanically, cockroaches walk through sewage, garbage, and decaying material before crossing food preparation surfaces and stored food, transferring Salmonella, E. coli, and other pathogens. Heavy infestations produce a characteristic musty odor that lingers in fabric and porous surfaces. Severity scales with population density, presence of children or asthmatic occupants, and how directly the infestation contacts food storage and preparation areas.

Solutions and Actions

German cockroach control relies on a gel bait program combined with insect growth regulators and sanitation, not contact sprays. Place small dots of gel bait (roughly fifteen to twenty per active room) in cracks, hinges, behind appliances, under sinks, and along plumbing penetrations — directly where activity is heaviest. Avoid spraying anywhere near bait because residue causes cockroaches to reject treated stations. Combine baiting with rigorous food removal: store dry goods in sealed containers, eliminate water access from leaks and drip pans, and remove cardboard. Replace bait every two to four weeks until monitors show no activity for thirty days. Larger species (American, oriental) respond best to perimeter treatment combined with drain maintenance and sealing exterior entry points.

Frequently Asked Questions

Do cockroaches eat everything?

Cockroaches are omnivorous scavengers with an extremely broad diet, but they do have preferences. They prefer starchy, sugary, and greasy foods. However, when preferred foods are unavailable, they can consume paper, glue, soap, leather, hair, and even other cockroaches. This dietary flexibility is one reason cockroaches are so difficult to starve out and why sanitation alone is often insufficient for elimination.

Will removing all food get rid of cockroaches?

Removing food sources alone will not eliminate cockroaches because they can survive on extremely small amounts of organic material and can go about a month without eating. However, reducing available food makes bait products more attractive relative to other food sources, significantly improving treatment effectiveness. Sanitation is a critical component of control but must be combined with active treatment methods.

What food attracts cockroaches the most?

Cockroaches are most attracted to starchy foods, sweet foods, greasy and fatty foods, fermented products like beer, and pet food left out overnight. Crumbs, grease splatters, food residue in drains, and unsealed garbage are the most common food attractants in homes. Even small amounts of food residue can sustain cockroach populations.

Do cockroaches eat cardboard and paper?

Yes. Cockroaches can feed on the starches, glues, and organic residues in cardboard, paper, book bindings, and paper bags. Cardboard also holds moisture and provides hiding space, which is why removing stored boxes is a useful sanitation step in infestations.