Oriental cockroaches are dark brown to nearly black roaches about 1 inch long. They live in cool, damp places: basements, crawl spaces, floor drains and sewers. In NYC buildings, they usually come up from the basement along pipes and drains. To get rid of them, dry out and seal the damp spots they live in, cover drains, and treat the basement and lower floors.
Spraying the ones you see won’t stop them. The roaches you see came from a damp spot you can’t see, and more will follow until that spot is fixed.
How to tell it’s an Oriental cockroach
According to Penn State Extension, Oriental cockroaches are:
- About 1 inch long
- Very dark brown to nearly black, often with a greasy shine
- Unable to fly. Females have only tiny wing pads. Males have short wings that cover about three quarters of the abdomen.
- Different by sex. Females are broader and heavier than males, so people sometimes think they’re two different bugs.
You may also notice a strong, musty smell where many of them live.
| Feature | Oriental | American | German |
|---|---|---|---|
| Size | About 1 inch | About 1 1/2 inches | 1/2 to 5/8 inch |
| Color | Dark brown to black | Reddish brown | Tan to light brown |
| Wings | Short or none, can’t fly | Full wings | Full wings, don’t fly |
| Where | Damp basements and drains | Basements, boiler rooms, sewers | Kitchens and bathrooms |
Oriental and American cockroaches both get called “water bugs.” See water bug vs. cockroach to tell what you’ve got, or our guide to roaches in NYC for all four common kinds.
What to do depends on where you saw it
In the basement, boiler room or laundry room
This is usually where they live, so start here. Put sticky traps along the walls and in the corners, and check them after a week. The traps with the most roaches point to the source. Then fix the leaks, clear out cardboard and trash, and add door sweeps to the basement doors.
Coming up a floor drain or tub
The roaches are living in the drain lines or the basement below. Cover drains you don’t use with a rubber cover or a metal screen, as the NYC Health Department’s pest guide suggests. Then tell your super so the basement gets checked.
In a first-floor apartment
They’re probably coming up along the pipes from the basement or a crawl space underneath you. Ask your super to seal the gaps around the pipes under your sink and behind the tub. Gel baits along the edges of the room help in the meantime.
On an upper floor
This is less common. Penn State says Oriental cockroaches are seldom found on upper floors, but Oklahoma State University Extension notes they can climb water pipes to the upper floors of apartment houses. One on a high floor usually means a bigger problem below, so the whole building should be checked.
Outside, near the building
In warm weather, they live outdoors under leaves, mulch and stone walls and in trash areas. A few outside isn’t a reason to treat inside. Keep the trash area clean and seal the gaps at doors, because dry spells push them indoors looking for water.
What doesn’t work
Foggers and bug bombs scatter roaches without reaching where they live, Penn State notes. Boric acid or silica dust can help in dry wall voids and cracks, but only if the damp spot is fixed too. In a building with three or more apartments, NYC’s Local Law 55 of 2018 says an owner’s pesticide treatments must be done by a pest professional licensed by New York State.
Here’s a simple example. Say the super of a walk-up building keeps finding large, dark roaches in the basement laundry room and near a floor drain. Killing the ones he sees doesn’t help: more turn up a week later, and tenants on the first floor start seeing them too. The source is a damp crawl space and the open drain. Fixing the leak, screening the drain, sealing the pipe openings into the first-floor apartments and having a licensed pro bait the basement stops them.
When to call a professional
Call a professional if you still see them after a few weeks of these steps, if they show up on several floors, or if the source is somewhere you can’t reach, like a crawl space or a wall.
NYC Extermination starts with a free on-site inspection of the basement, the drains and the units around the problem. Then we treat with targeted, EPA-registered products and seal the gaps roaches travel through. For landlords and managers, we plan pest control for the whole building. See our cockroach exterminator service or call (347) 988-2315.
Frequently asked questions
I found one Oriental cockroach in my house. Are there more?
Probably. One usually means more in a damp spot nearby, like the basement, a crawl space or a drain. Set sticky traps for a week to see how many there are and where they’re coming from.
What’s the fastest way to get rid of Oriental cockroaches?
Fix the moisture first, then treat where they live. A dry basement, covered drains and sealed pipe gaps leave them nowhere to go, and baits finish off the ones that are left.
Are Oriental cockroaches dangerous?
They very rarely bite people, but like other roaches they can contaminate food and make asthma worse, according to the NYC Environment and Health Data Portal. Clean up where they’ve been and keep food sealed.
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