What Do Cockroaches Eat? Diet, Food Sources and Feeding Habits

Most people only notice cockroaches when a kitchen light flicks on late at night, and that is usually when the question shows up: what are they actually eating? The short answer is almost anything organic, and Encyclopaedia Britannica (general reference encyclopedia) describes them as mostly scavengers, so the clues they leave behind in a home tell you more about their menu than any species list will.

Diet type: Generally omnivorous · Most attractive foods: Starch, sugar, grease, meat, cheese · Documented feeding substrates: Bread, fruit, leather, book-binding starch, paper, glue, skin flakes · Waste and carrion feeding: Garbage, dead animals, feces

Eight data points, one pattern: the diet is broad, while survival times and feeding preferences split sharply by species.

What can cockroaches eat?

Cockroaches are generalists, not picky specialists, and the menu is long. Encyclopaedia Britannica, a general reference encyclopedia, says they eat both plant and animal products, including food, paper, clothing, books and dead insects.

Sugar, starch and fat draw them in most strongly. A peer-reviewed pathogen study in PubMed Central reports that cockroaches are omnivores that eat any organic food, though they prefer sweets, meat products, starches and grease.

What do cockroaches eat in the wild?

• Outdoors, American cockroaches mainly feed on dead or decaying plant material and organic matter, according to Orkin Canada (pest-control company guidance).
• Cockroaches are detritivores that digest lignocellulose in plant matter and release nitrogen into soil through their droppings (PubMed Central (NIH author manuscript on cockroach biology)).

What do cockroaches eat and drink?

• Water is the tighter limit: UK PestAware guidance says cockroaches can survive for months without food but will not live more than a few days without water (British Pest Control Association, trade-body guidance).
• Laboratory colonies are commonly fed dog pellets, rodent feed, ground biscuits and fresh fruit, per an NIH author manuscript on cockroach biology, which shows how broadly they accept food.

The implication: the menu is set by opportunity, not by a fixed list, which is why the same species can scavenge dead leaves outdoors and raid a pantry indoors.

Do cockroaches eat poop?

Yes, and the detail matters. Feces appears in published food lists, but the bigger concern is what the insects carry away from it: cockroaches often feed on human feces and can mechanically spread intestinal parasite cysts (Scientific Reports, via PubMed Central, peer-reviewed pathogen study).

• Feces-eating is most common in early German cockroach nymphs, which take in gut microflora and nutrients from fecal pellets when they gather in groups (NC State Extension, university extension research).
• According to Raid, a consumer pest-control brand, cockroaches can transfer pathogenic microbes to food and cooking surfaces by walking across them, which can cause food poisoning and diarrhoea.

Do cockroaches eat dead insects?

• German cockroaches regularly consume other German cockroaches who have died, a food source that matters most to life stages that spend long periods hidden in groups (NC State Extension, university extension research).
• Starvation can drive cannibalism, a behaviour a peer-reviewed review documents directly (PubMed Central, peer-reviewed review).

The implication: waste feeding turns a diet question into a sanitation question, so the bin and the drain matter as much as the species name.

Where do cockroaches live?

Habitat sets the menu, because a roach can only eat what it can reach.

• German cockroaches are mainly indoor insects. According to Rentokil (commercial pest-control company), they favour humid, warm, secluded spots near food, such as kitchens, dining rooms and bathrooms.
• American cockroaches are mainly outdoor insects that eat decaying plant matter, and they move into homes in heat or drought, according to Rentokil, a commercial pest-control company.

Why do cockroaches suddenly appear?

• Access to food and water shapes where roaches gather indoors, and Rentokil notes that heat or drought can push American cockroaches inside.
• The sources tie indoor gathering to food access, so the first place to check is the kitchen.

The implication: habitat and food access are the same question, so the feeding evidence in the next section also maps where the roaches are.

What are the signs of a cockroach infestation?

Feeding evidence is indirect, and the sources reviewed here are clearer on food access than on field indicators. Sweets, meat products, starches and grease are the strongest draws, which makes those spots the first place to look, according to a peer-reviewed pathogen study in PubMed Central.

Virginia Cooperative Extension’s control guidance starts from the same place: the food and water a roach can reach.

What smells do cockroaches hate?

• The sources reviewed here do not identify a smell that reliably keeps cockroaches away, so this article makes no repellent claim.
• What the sources do agree on is the food side of control: eliminate food, water and shelter, and seal cracks, per Virginia Cooperative Extension, university extension guidance.

The catch: the research gives control guidance but no verified checklist of droppings or smear marks, so reading residue is an inference from feeding habits rather than a field-tested method.

What do cockroaches do to humans?

Direct contact is uncommon in the sources reviewed, and the real link to people runs through food and waste.

• According to Orkin Canada (pest-control company guidance), cockroaches bite humans only rarely, generally only in extreme infestations where other food sources are depleted.
• American cockroaches eat dried skin flakes, hair and dead animals, among other items (GBIF species record, global biodiversity database).

Do roaches go near sleeping people?

• The sources reviewed here do not document roaches seeking out sleeping people, so this article makes no claim either way.
• Feeding on dead bodies is documented, and forensic accounts describe postmortem marks that can resemble antemortem trauma, abrasions or burns, with the earliest accounts dating to the late 1800s (Oxford Academic, Journal of Economic Entomology).

The implication: the human risk comes from what cockroaches carry out of food and waste, so cleaning up residue does more than chasing a bite question.

“Cockroaches are mostly scavengers, consuming both plant and animal products.”

Encyclopaedia Britannica (editorial entry)

“Cockroaches are not fussy eaters; they are omnivores which means they will feed on almost anything, including refuse, faecal matter and even other cockroaches.”

BPCA PestAware (UK pest-control trade body)

A generalist that eats paper, glue and other cockroaches does not depend on any one food, so removing a single snack rarely ends an infestation. Virginia Cooperative Extension treats the problem as food, water and shelter together. For a homeowner, the choice is clear: remove food, water and shelter as one job and seal the cracks, or expect a generalist to keep finding its next meal.

Related reading: foods high in protein

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