Cockroaches are highly adaptable, opportunistic scavengers with a remarkably broad diet. These omnivorous insects consume both plant and animal matter, thriving on a wide array of organic materials. Their varied diet is a key factor in their ability to survive and infest human habitats.
Common Dietary Habits
In human environments, cockroaches primarily seek readily available food sources. They are attracted to common household items like food crumbs, spills, and grease. Discarded edibles, including fruits, vegetables, and meats, are also highly appealing. Cockroaches also consume pet food. Their strong sense of smell helps them locate food particles.
They prefer sugary, starchy, and greasy foods. Fermented or moldy foods are also favored, often leading them to garbage cans. German cockroaches are especially drawn to sweets, starches, and meat products.
Unconventional Food Sources
When preferred food sources are scarce, cockroaches consume a variety of non-obvious items. This includes glue in book bindings, wallpaper paste, and cardboard boxes, which contain starches and cellulose. They also eat soap, toothpaste, and human organic matter like dead skin cells, hair, and fingernails, which contain keratin.
Cockroaches possess digestive enzymes, including amylase, lipase, and proteinase, that break down various food components. Some species also harbor symbiotic bacteria that digest cellulose, expanding their diet to include decaying wood. When food is extremely limited, some cockroach species resort to cannibalism, feeding on molted shells, eggs, or other dead cockroaches.
Survival Without Sustenance
Cockroaches are resilient, enduring extended periods without food. Most species survive about a month without eating, though larger species like the American cockroach might last up to three months. This prolonged survival is due to their low metabolic rate, which conserves energy efficiently.
Their need for water is more frequent. Cockroaches typically cannot survive more than a week without water, as they are susceptible to dehydration. Survival time depends on the specific species, environmental temperature, and humidity levels, with humid conditions being more favorable.
Practical Implications for Control
Understanding the dietary habits of cockroaches is important for effective pest management. A primary strategy involves limiting their access to food and water sources within a home or building. This includes maintaining a high level of cleanliness, such as promptly wiping up spills and crumbs from floors and countertops.
Proper food storage is also essential; all food items, including pet food, should be kept in airtight containers. Managing waste by using tightly covered garbage bins helps eliminate another significant food attraction. This knowledge also informs the development of cockroach baits, which are formulated with attractive food-grade ingredients combined with insecticides to lure and eliminate the pests. These baits exploit the cockroaches’ feeding behavior, as they consume the bait and can then transfer the insecticide to others in their colony.