# Smoky brown cockroach (Periplaneta fuliginosa) > A large, uniformly dark-brown outdoor-associated cockroach that commonly invades homes for moisture and shelter, attracted to lights at night. Source: https://insectscanner.com/species/smoky-brown-cockroach/ (updated 2026-10-10) ## Is it dangerous? **Allergen potential.** Smoky brown cockroaches do not bite or sting as a defensive behavior and are not venomous, but they contaminate food and surfaces with bacteria and allergens; exposure can worsen asthma and allergic reactions. If handling is necessary, use gloves and clean any exposed food or surfaces. For heavy infestations, consider professional pest control. **Pets:** Can carry bacteria and allergens that may affect pets; not poisonous, and direct attacks on pets are extremely rare. Pets that ingest many cockroaches can develop stomach upset. ## Quick facts - Scientific name: Periplaneta fuliginosa - Order: Blattodea (Cockroaches and termites) - Family: Blattidae (Cockroaches) - Size: About 30-40 mm body length - Colours: Dark brown, Chestnut brown, Tan (nymphs) - Habitat: Prefers moist outdoor habitats: tree cavities, leaf litter, mulch, compost, storm drains; enters buildings seeking moisture and shelter - Range: Native to East Asia; now established in warm temperate and subtropical regions worldwide, including the southeastern United States, Hawaii, parts of Australia and other warm regions - Active: Nocturnal; active year-round in warm climates and in heated buildings; peak activity at night - Lifespan: Several months to over a year for adults depending on temperature and resources - Effect on plants: Scavenger - Pest: yes ## Overview Periplaneta fuliginosa is a medium-to-large cockroach species often found around lights, tree holes, mulch and other moist outdoor sites; it will enter buildings when conditions are favorable. Adults are strong fliers and most active at night. They are omnivores and scavengers, feeding on decaying plant matter, food debris and other organic material. While not aggressive or venomous, they are nuisance pests that can contaminate food and trigger allergies or asthma in sensitive people. ## How to identify it Adults are uniformly dark brown to nearly black, with long, flat, oval bodies and fully developed wings that extend past the abdomen. Males are typically slightly smaller with longer wings and better flight ability; females are broader. Nymphs are wingless and more reddish-brown, becoming darker as they mature. Unlike some other Periplaneta, smoky browns lack pale margins or conspicuous banding on the pronotum or wings. - Uniformly dark brown to nearly black adult with fully developed wings that extend beyond the abdomen - Body length about 30-40 mm, flattened oval shape typical of Periplaneta cockroaches - Attracted to light at night and commonly found around tree cavities, mulch and other moist outdoor sites - Males are more slender and better fliers than females; nymphs are wingless and lighter in color ## Lookalikes - **American cockroach** (Periplaneta americana): Larger and more reddish (reddish-brown) with a pale margin on the pronotum; P. americana is often bigger than smoky brown cockroaches. - **Oriental cockroach** (Blatta orientalis): Shiny black-brown; females have only tiny wing pads and males have wings shorter than the abdomen, so neither can fly. Smoky browns are fully winged and strong fliers. - **Brown-banded cockroach** (Supella longipalpa): Much smaller and has distinctive light bands across the wings and abdomen; smoky browns are larger and lack banding. ## Life cycle - **Egg (ootheca):** Females produce an egg case (ootheca) containing multiple eggs (typical Periplaneta egg counts are around two dozen); the female may deposit it in sheltered, humid sites. - **Nymph:** Wingless young that molt repeatedly, gradually darkening and growing larger; nymphal development time depends on temperature and food availability. - **Adult:** Sexually mature, winged cockroaches capable of flight (especially males); adults reproduce and continue scavenging. ## Diet and predators - Young eat: Decaying plant material, organic debris, crumbs and other scavenged foods - Adults eat: Same as juveniles — omnivorous scavengers that eat decaying organic matter, food scraps, paper and glue - Predators of the young: Spiders, centipedes, ants, small vertebrates and predatory insects - Predators of adults: Birds, frogs, toads, small mammals, predatory insects and some spiders; humans use trapping and insecticides ## Effect on plants and gardens Primarily a scavenger on decaying plant material and organic debris; not a significant plant pest ### How to get rid of it Reduce moisture and food sources: fix leaks, remove mulch or wood-touching foundations, store food in sealed containers, clean up pet food and crumbs. Seal gaps and entry points with caulk or weatherstripping. Outdoors, reduce outdoor lighting that attracts them or use yellow 'bug' lights. Use baits (gel or bait stations) and insecticidal baits targeted at cockroaches; residual sprays or insect growth regulators can help in severe infestations — consider a licensed pest professional for large or persistent problems. ## Where and when to find it Look outdoors at night around porch lights, exterior walls, tree trunks, mulch, compost piles and drains; indoors check basements, crawlspaces, attics and areas with high humidity. - Best time: Warm months and nights; nocturnal — best observed after dark near lights or moist shelter. - Tips: Use a flashlight to observe at night; they are attracted to white or bright lights. Photograph dorsal view to capture the uniform dark coloration and wing length for identification. ## Fun facts - Smoky brown cockroaches are strongly attracted to lights and are often seen flying toward porch and security lights at night. - Unlike many other common household cockroaches, smoky browns are frequently found outdoors and can live year-round outside in warm climates. - Adults are capable of sustained flight, especially in warm, humid conditions. ## Frequently asked questions ### Do smoky brown cockroaches bite? Bites are rare. They are not aggressive toward humans and usually avoid contact; any bite would be incidental and not venomous. ### Are smoky brown cockroaches dangerous? They are not venomous but can contaminate food and surfaces with bacteria and trigger allergies and asthma in sensitive people. ### Why do I have smoky brown cockroaches in my house? They enter seeking moisture, shelter and food. Outdoor populations close to foundations, damp mulch, clogged gutters or tree cavities often lead to occasional indoor invasions. ### How do I get rid of smoky brown cockroaches? Start with sanitation and moisture control, seal entry points, reduce outdoor lighting near doors, and use cockroach baits or bait stations. For heavy infestations, use professional pest control. ### Where do smoky brown cockroaches live? They prefer warm, humid environments: tree cavities, leaf litter, compost, mulch, drains and other moist outdoor shelters, as well as basements and crawlspaces in buildings. --- More about this species: [iNaturalist](https://www.inaturalist.org/taxa/1649048). Identify insects and spiders from a photo with the Insect Scanner iPhone app: https://apps.apple.com/app/id1543946563?pt=126685406&ct=web-markdown&mt=8 Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.