A
Species Profile

American Cockroach

Periplaneta americana

Sewer sprinter with a global passport
Fajar Tri Amboro/Shutterstock.com

American Cockroach Distribution

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Invasive Species
Origin Location

This map shows the native origin of the American Cockroach. As a cosmopolitan species, they are now found worldwide.

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American cockroach

At a Glance

Found Worldwide
Also Known As Palmetto bug, Waterbug, Roach, Red runner
Diet Omnivore
Activity Nocturnal+
Lifespan 12 years
Weight 0.0015 lbs
Status Not Evaluated
Did You Know?

Adults are typically 28-44 mm long, making it one of the largest common urban cockroaches (Bell, Roth & Nalepa, 2007).

Scientific Classification

A large blattid cockroach species widely distributed globally (often in warm urban environments) and commonly considered a pest; despite the name, it likely originated in Africa and spread via commerce.

Kingdom
Animalia
Phylum
Arthropoda
Class
Insecta
Order
Blattodea
Family
Blattidae
Genus
Periplaneta
Species
Periplaneta americana

Distinguishing Features

  • Large size relative to many household roaches (often ~3–4 cm adult length)
  • Reddish-brown coloration with a pale/yellowish margin on the pronotum
  • Long antennae; fully developed wings in adults (can glide/short flights)
  • Fast-running, prefers warm and humid microhabitats

Physical Measurements

Length
2 in (1 in – 2 in)
Weight
0 lbs (0 lbs – 0 lbs)
Top Speed
3 mph
Top speed about 5.47 km/h

Appearance

Primary Colors
Secondary Colors
Skin Type Hard, smooth, glossy chitinous exoskeleton (sclerotized cuticle) with membranous hind wings beneath leathery forewings (tegmina) in adults.
Distinctive Features
  • Adult body length about 3.5-4.0 cm (large domestic/pest cockroach); dorsoventrally flattened body with a broad pronotum.
  • Pronotum shows a pale yellow marginal band surrounding a darker central area (key field diagnostic character).
  • Adults have fully developed wings: forewings (tegmina) cover the abdomen; capable of gliding/short flights, especially in warm conditions.
  • Very long filiform antennae (often approximately body-length or longer), aiding nocturnal foraging and navigation.
  • Ootheca (egg case) is dark brown; commonly reported at ~0.8 cm long and typically contains 14-16 eggs (often 16).
  • Nymphs are wingless and progressively develop wing pads over multiple molts (typically 10-13 instars reported), leaving shed skins (exuviae) as a common infestation sign.
  • Typical pest-ecology signs associated with this species include: cylindrical fecal droppings commonly ~0.1-0.2 cm long with longitudinal ridging; scattered exuviae; and a characteristic musty/"cockroach" odor from aggregation/defensive secretions in heavy infestations.
  • Habitat association relevant to field recognition: often encountered in warm, humid urban environments (e.g., sewers, drains, boiler rooms, basements), where moisture and heat support large-bodied individuals.

Sexual Dimorphism

Sexes are similar in overall color and pattern, but differ subtly in abdominal tip morphology and wing length; males also bear genital-associated structures (styli) absent in females.

♂
  • Wings typically extend beyond the tip of the abdomen (often visibly longer than the abdomen).
  • Paired styli present on the ventral subgenital plate at the abdominal tip (diagnostic in hand specimens).
  • Generally slightly more slender abdomen compared with females.
♀
  • Wings typically reach to about the end of the abdomen or may be slightly shorter than the abdominal tip (less abdominal overhang than males).
  • Broader, more rounded abdomen when gravid; lacks styli on the subgenital plate.
  • Often seen carrying or depositing an ootheca during the reproductive period (egg case protruding from abdomen shortly before deposition).

Did You Know?

Adults are typically 28-44 mm long, making it one of the largest common urban cockroaches (Bell, Roth & Nalepa, 2007).

A female carries and then drops a bean-shaped egg case (ootheca) that usually holds 14-16 eggs (Bell, Roth & Nalepa, 2007).

Embryos commonly hatch in ~35-60 days depending on temperature and humidity; warmer conditions speed development (Bell, Roth & Nalepa, 2007).

Nymphs pass through ~9-13 molts (instars) before adulthood, so shed skins (exuviae) are a frequent clue in infestations (Bell, Roth & Nalepa, 2007).

From egg to adult can range from ~5 months to well over a year depending on temperature/food; adults often live several months under indoor conditions (Bell, Roth & Nalepa, 2007).

Despite the name, it likely originated in Africa and spread worldwide via trade routes, becoming entrenched in ports, sewers, and heated buildings (Bell, Roth & Nalepa, 2007; common historical accounts).

In parts of China, Periplaneta americana is commercially reared for extracts used in modern Traditional Chinese Medicine products (e.g., "Kangfuxin" preparations), giving it an unusual role beyond "pest" status (pharmacopoeial/industry usage).

Unique Adaptations

  • Diagnostic pronotum: a reddish-brown shield (pronotum) with a distinctive pale/yellowish margin around it-one of the quickest field marks for P. americana.
  • Water-management physiology: a waxy cuticle and efficient excretion help reduce water loss, supporting survival in intermittently dry indoor spaces while still favoring high humidity.
  • High-sensitivity rear sensors: paired cerci at the abdomen tip detect faint air currents, triggering rapid escape responses studied extensively in neuroethology (classic cockroach escape-circuit research).
  • Generalist digestive toolkit: able to exploit a broad range of human-associated foods and decomposing matter, aiding success in sewers and buildings.
  • Protective egg packaging: the ootheca shields embryos from desiccation and minor physical damage, improving survival in harsh urban microhabitats.
  • Claw-and-pad locomotion: tarsal claws and adhesive pads help it climb rough surfaces and move efficiently through complex, vertical urban infrastructure (pipes, masonry, utility shafts).

Interesting Behaviors

  • Nocturnal foraging: most activity peaks at night; daytime sightings often indicate overcrowding or disturbed harborages.
  • Thigmotaxis ("wall-hugging"): prefers tight cracks/crevices where the body contacts surfaces above and below, explaining why it favors utility chases, cabinets, and sewer junctions.
  • Ootheca handling: the female carries the ootheca for a period (often hours to a couple of days) and then deposits it in a protected crevice near food/water; empty cases may accumulate in hidden sites.
  • Omnivorous scavenging: feeds on starchy foods, grease, decaying organic matter, and even book bindings or hair; in sewers it readily uses biofilms and organic waste.
  • Aggregation behavior: forms groups in harborages guided by odors from feces, cuticular chemicals, and aggregation pheromones-why finding one often means a nearby harborage.
  • Moisture-seeking: strongly associated with warm, humid microhabitats (boiler rooms, steam tunnels, floor drains); will track along plumbing and condensation lines.
  • Short glides/flight: adults have fully developed wings; they may flutter or glide (especially in warm conditions), though they more often run than fly.
  • Infestation "tells": pepper-like droppings, a persistent musty/oily odor, smear marks along runways, shed nymphal skins, and discarded oothecae in crevices.

Cultural Significance

The American cockroach (Periplaneta americana) is a common warm-city pest tied to sewers, subways, drains, and damp basements. It's used in labs to study insect nerves and behavior and is raised for some medicines and extracts.

Myths & Legends

Linnaeus named it Blatta americana in 1758, and the 'americana' name stuck even though Periplaneta americana likely came from Africa — an example of early trade-era naming that called a global species wrong.

In many coastal cities, large "palmetto bugs" or "waterbugs" (often Periplaneta americana) are folk signs of wet weather; people link indoor sightings to rain or sewer trouble, showing the bug's link to damp infrastructure.

In North American city stories, the American cockroach (Periplaneta americana) is the "sewer roach" symbol of the undercity, a tough night dweller in subway and steam-tunnel tales and urban humor.

Conservation Status

NE Not Evaluated

Has not yet been evaluated against the criteria.

Population Unknown

Life Cycle

Birth 16 nymphs
Lifespan 12 years

Lifespan

In the Wild
6–18 years
In Captivity
12–30 years

Reproduction

Mating System Promiscuity
Social Structure Aggregation Group
Breeding Pattern Transient
Fertilization Internal Fertilization
Birth Type Internal_fertilization

Periplaneta americana is a promiscuous cockroach with internal fertilization. They live in loose groups; females release pheromones, males court and transfer a spermatophore. Females store sperm, make many oothecae (~14–16 eggs), and show no parental care.

Behavior & Ecology

Social Aggregation Group: 20
Activity Nocturnal, Crepuscular
Diet Omnivore carbohydrate-rich foods (especially sugars and starches; e.g., fruit residues and baked/grain products)

Temperament

Gregarious (aggregation-prone)
Strong negative phototaxis (avoids light; emerges mainly after dark)
Positive thigmotaxis (prefers tight contact with surfaces; crowding in harborages)
Rapid escape/avoidance when disturbed; not territorial
Opportunistic omnivorous scavenger; cannibalism can occur under crowding or food limitation (reported in blattids; Bell, Roth & Nalepa 2007)

Communication

Sex pheromones: females emit volatile periplanones Notably periplanone-B; also periplanone-A reported) that elicit long-range male orientation and courtship (Persoons et al., identification work on Periplaneta americana sex pheromones; summarized in Bell, Roth & Nalepa 2007
Aggregation cues: conspecific feces/harborage-conditioned substrates contain aggregation signals that recruit and retain individuals at shelter sites Behavior widely documented for cockroaches; Bell, Roth & Nalepa 2007
Contact chemoreception via antennae and tarsi Antennation and substrate tasting) used for social spacing, mate assessment, and following chemical trails/harborage cues (Bell, Roth & Nalepa 2007
Tactile signaling/interaction: antennal touching and body contact within dense shelters; supports aggregation maintenance and recognition of immediate conspecific presence Hub pattern across gregarious blattids
Substrate-borne vibration sensitivity: detects footsteps/disturbance and conspecific movement through the substrate, contributing to coordinated retreat into harborages General cockroach sensory ecology; Bell, Roth & Nalepa 2007

Habitat

Biomes:
Tropical Rainforest Tropical Dry Forest Savanna Mediterranean Temperate Forest Temperate Grassland Wetland Boreal Forest (Taiga) +2
Terrain:
Coastal Plains Island Riverine
Elevation: Up to 8202 ft 1 in

Ecological Role

Urban omnivorous scavenger/detritus-feeder that accelerates breakdown of organic wastes and serves as prey for predators (e.g., spiders, geckos, rodents, birds) while also acting as a potential mechanical vector of microbes in built environments.

decomposition of organic refuse and waste nutrient recycling/mineralization in detrital food webs supporting urban food webs as prey biomass redistribution of organic matter and microbes via foraging and fecal deposition

Diet Details

Main Prey:
Small arthropods Invertebrate carrion Animal tissue scraps Animal-derived waste
Other Foods:
Starchy plant-derived foods Sugary fermenting plant material Leaf litter Fungi and microbial biofilms Cellulose-containing materials

Human Interaction

Domestication Status

Wild

Periplaneta americana is a wild species that lives near people and is not domesticated. It likely came from tropical Africa and spread worldwide by ships and trade in the 1500s–1600s. People mainly control it as a pest in buildings, sewers, and food areas; it is also used in labs, classrooms, and as feeder insects.

Danger Level

Moderate
  • Allergen source: cockroach feces, saliva, shed skins, and frass contribute to indoor allergens and asthma morbidity; cockroach allergens are well-established triggers in sensitized individuals (e.g., WHO/IUIS allergen literature; Schal & Hamilton, 1990s; Arruda et al., 2001).
  • Mechanical transmission risk: can carry and disseminate bacteria/other microbes picked up from sewers, garbage, and drains onto food-contact surfaces (reviewed in Rust, Owens & Reierson, 1995; and subsequent medical-entomology reviews). This is typically considered mechanical carriage rather than biological 'vector' competence.
  • Food contamination and tainting: odor and fecal spotting can render stored food/packaging unsaleable (Rust et al., 1995).
  • Occasional opportunistic nibbling/bites are rare but reported, usually when populations are high and food is scarce (Rust et al., 1995).

As a Pet

Suitable as Pet

Legality: American cockroach (Periplaneta americana) is usually legal as a pet or feeder in much of the U.S., but some places ban keeping, moving, or releasing pest insects. Check local agriculture or health rules first.

Care Level: Moderate

Purchase Cost: Up to $15
Lifetime Cost: $50 - $250

Economic Value

Uses:
Public health & sanitation (negative) Structural/urban pest management (negative) Food handling/commerce impacts (negative) Research/education (positive) Pet trade/feeder insect (minor positive)
Products:
  • Pest-control services and insecticide baits/traps targeted at Periplaneta americana infestations
  • Laboratory use in physiology/neurobiology/toxicology (standard large-cockroach model organism)
  • Feeder insects for reptiles/amphibians/invertebrate pets (captive-bred colonies)
  • Educational/live demonstration animals in classrooms and museums

Relationships

Related Species 5

American cockroaches are genetically similar to the termite.

The American cockroach, sometimes referred to as a waterbug in the United States, is a nocturnal pest that originated in Africa and the Middle East. It is believed that these roaches traveled to America for the first time aboard Atlantic slave trade ships sometime around 1625. They are the largest species of cockroach, live the longest, and can actually fly short distances when necessary. Despite their nickname, these bugs do not live in water. But they do prefer warm, moist environments over desert regions. Their life cycle includes three stages including eggs, nymphs, and adults. The egg gestation period is six to eight weeks.

As omnivorous scavengers, these common cockroaches will eat just about any organic matter. They prefer meats, starches, and sweets. But they are known to consume just about anything organic, including decaying matter, books, and hair.

4 Incredible American Cockroach Facts!

The eyes of American cockroaches are far more sensitive to light than the human eye.

  • They can run 3.4 miles per hour, equivalent to a human running 210 miles per hour.
  • Each eye has over 3,500 individual lenses.
  • Roaches scamper when you turn on the lights because their eyes are far more sensitive to light than the human eye.
  • In the second life cycle between eggs and adults, nymphs can regrow lost legs.

Species, Types, and Scientific Name

American cockroach on wood

Not only found in North America, the American cockroach is now found in Spain, Portugal, and the Canary Islands.

The American cockroach is a member of the genus Periplaneta, a classification of large urban-dwelling cockroaches of the family Blattidae and order Blattodae. There are 47 cosmopolitan species of roaches in Periplaneta and about 4,400 species of cockroaches and termites in the order Blattodae. The American cockroach is now found in Spain, Portugal, the Canary Islands, and throughout North America. Along with other types of cockroaches in specific areas, the American roach can make up as much as 24% of the animal biomass.

Appearance: How to Identify

close up of an American cockroach

The American cockroach is the largest species among common cockroaches with a length of 1.6 inches.

American cockroaches and other species of roaches are genetically similar to the termite. This is why scientists have reclassified termites and roaches into the same order, Blattodae.

American cockroaches are reddish-brown in color with some yellow features, such as just behind the head. These are the largest species among common cockroaches, with an average length of 1.6 inches and a height from the surface of about 0.28 inches. But they are not as sizeable as the largest flying cockroach ever found in the world. That is Megaloblatta longipennis found in Peru, Ecuador, and Panama with one flying specimen measuring 3.8 inches in length with a wingspan of eight inches.

Their bodies have three sections: the head, thorax, and abdomen. Overall, the body is flat and wide in an oval shape, weighing between 0.8 and 1.4 grams at adulthood. Its head features a shield-like covering called a pronotum. At close range identification of the roach’s chewing mouth parts is possible. They also have long antennae and two sets of wings, some of their most important features. The fore wings are stronger and leathery while the hind wings are delicate and thin. While the American cockroach typically crawls on surfaces, a startled roach of this species is capable of flying short distances.

Because these roaches are nocturnal, you generally will happen upon one or multiple at night. Turning on a bright light will startle them into quick motion at high speed. They will scamper away when perceiving a threat like a human entering a room. Sensitivity to vibrations makes them run from slamming doors, clapping, foot stomping, and other sudden sounds and movements.

American cockroaches go through three stages in their life cycle, from egg to nymph and then adult. Their young, the nymphs, look just like adults but do not have wings. They molt an average of 13 times before metamorphosis. The nymphs can regenerate limbs, whereas adults cannot. Senior American cockroaches have trouble crawling up walls or along surfaces because of their age.

These roaches live in colonies called intrusions. An intrusion works together to find food and other resources. Upon a small group of scouts’ identification of food or water, they release a distinct tracking odor called an aggregation pheromone to signal the rest of the colony to join them. Because members of one roach colony do not all come out at once, the number you see is just a mere fraction of the actual colony size. When roaches infest homes, they are called infestations.

Habitat: Where to Find

The American cockroach’s body is made up of three sections: the head, thorax, and abdomen.

These pests prefer living close to easily scavenged food sources and live both above ground in buildings and below ground in basements, sewers, and other underground systems they use as superhighways to food sources. You can find them living in your walls, kitchen, bathroom, cabinets, basement, crawl spaces, lawn, and under other man-made structures like sidewalks, garbage receptacles, storage buildings, and porches.

These pests carry at least 22 species of harmful bacteria, viruses, fungi, and protozoans that can infect humans. They also carry five species of parasitic worms. One of their biggest threats to humans is the pests’ production of airborne allergens, proteins that cause asthma attacks, and allergic reactions.

American cockroaches can scamper out of view at speeds up to 3.4 miles per hour. This is the equivalent of a human running 210 miles per hour. They run away because of threat identification and as a reaction to light. Their eyes have over 3500 lenses, making them more sensitive to light than humans. They can easily run under doors and through very small cracks, crevices, and gaps. Because they are nocturnal, they are most easily seen at night.

Diet: What Do American Cockroaches Eat?

What Do Cockroaches Eat
Cockroaches are scavengers and will eat just about anything that they find.

American common roaches are opportunistic scavengers. As true omnivores, they will eat just about any organic matter. Have a look at our “What Do Cockroaches Eat?” page for a complete list of everything that a cockroach eats.

What eats the American cockroach?

Many small mammals, amphibians, spiders, birds, and reptiles eat American cockroaches. Their predators vary according to the location and habitat. For example, in tropical environments, predators include spiders, ants, and mantids. Toads, fish, frogs, turtles, salamanders, lizards, and geckos also eat them. Mammalian predators include cats, mice, rats, monkeys, opossums, and porcupines. However, the roaches often carry viruses and parasites. They can pass these on to humans, as well as animals that eat them. Some of the parasites they carry include wasps, fungi, bacteria, and protozoa. Some wasps also eat American cockroach eggs, laying eggs within the roach egg sacs to sustain the wasp’s young.

What does the American cockroach eat?

They eat man-made food products, decaying plant matter, plant shoots, vegetables, fruits, meats, sugar, starches, decomposing animals, solid waste, and even ear wax from the inside of a human or animal ear. They will eat book bindings, hair, cosmetics, milk, soap, glue, wallpaper paste, and fabrics. Some studies suggest they eat about half of their body weight each day.

Prevention: How to Get Rid of American Cockroaches

Periplaneta_americana_25367901447

A professional exterminator can apply a residual spray to kill roaches at all of their life stages.

American cockroach colony infestations are notoriously difficult to exterminate. It is best to fight these pests both inside and outside of the home or structure at the same time. Start by caulking cracks and joints in ground-level walls, clearing away rotting leaves or other debris, and reducing moist areas around the structure. Then apply insecticides on basement walls perimeters, wood piles, and other places where the infestations have occurred. A professional exterminator can apply residual spray throughout the household and around its perimeter to kill roaches at all of their life stages, including those in egg sacs during the gestation period. Another method involves the use of poisonous pellet baits.

American Cockroaches vs. German Cockroach

German cockroaches are more common than the American variety.

One of the biggest differences between the American cockroach and the German cockroach is size. The American pests measure 1.5 inches on average, whereas the German variety is much smaller, typically only 1/2 inch in length. German roaches are also lighter in color, being tan with dark lines running their length whereas American roaches are reddish brown. American cockroaches are also often found in moist places their German counterparts do not frequent, such as basements, drains, and crawlspaces. German cockroaches typically show themselves in kitchens and bathrooms. However, homes are more likely to experience a German cockroach infestation than an American cockroach problem. This is simply because German roaches are more common.

Origin and Evolution

Periplaneta_americana_-_D8-10-2863p

American cockroaches originated from Africa and the Middle East. They traveled on commercial ships, such as those of the Atlantic slave trade, to North America and Spain in the 1700s, though records indicate it could be as early as 1625. From there, the roaches inhabited anywhere people live, eat, or dispose of waste. Today they are found throughout Spain, Portugal, the Canary Islands, and North America.

The American cockroach has specific traits and enlarged groups of genes relating to detoxification, the immune system, and growth and reproduction, which could be the reason it has been able to adapt to human living spaces.

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Sources

  1. Wikipedia / Accessed October 12, 2021
  2. PestWorld.org / Accessed October 12, 2021
  3. Orkin / Accessed October 12, 2021
  4. UFIFAS / Accessed October 12, 2021
  5. Penn State Extension / Accessed October 12, 2021
  6. Terminix / Accessed October 12, 2021
  7. Arrow Exterminators / Accessed October 12, 2021
  8. MSU Plant & Pests Diagnostics / Accessed October 12, 2021
  9. Extension Entomology / Accessed October 12, 2021
  10. Orkin Canada / Accessed October 12, 2021
  11. nature communications / Accessed October 12, 2021
  12. American Pest / Accessed October 12, 2021
  13. Adams / Accessed October 12, 2021
  14. PESTCO / Accessed October 12, 2021
  15. UF Book of Insect Records / Accessed October 12, 2021
  16. Cockroach Zone / Accessed October 12, 2021
Bethany McKay

About the Author

Bethany McKay

Bethany is a professional copywriter and editor, working with newspapers, small businesses, Fortune 500 companies, and everything in-between. She graduated from Penn State University with degrees in journalism and international studies. She loves her cat, Maggie, and has had numerous pets over the years, including guinea pigs, hermit crabs, fish, and a red-eared slider turtle. She lives among farmlands in southcentral PA and enjoys gardening, cooking, reading, and sewing.
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American Cockroach FAQs (Frequently Asked Questions)

American cockroaches are dangerous in large numbers, in that they carry pathogens and parasites. These pathogens can make people sick. They are particularly known for causing allergy problems and asthma attacks through the release of airborne protein allergens.