If you’ve spotted a shiny black bug crawling near your basement drain or hiding in your crawl space, you’re probably dealing with oriental cockroaches. In my experience as a registered technician in the DC metro area, German, oriental, and American roaches are among the most common species we encounter. Oriental cockroaches—often called “water bugs”—are especially common in homes with moisture issues.
These roaches are different from the smaller German roaches you might find in kitchens. They’re bigger, darker, and absolutely dependent on damp environments. The good news? Once you understand what attracts them, you can take steps to get rid of oriental cockroaches and keep them from coming back.
How to Identify Oriental Cockroaches
Before you can get rid of oriental cockroaches, you need to make sure that’s what you’re dealing with. These roaches have some unique features that set them apart from other species.
Size and color: Oriental cockroaches are about 1 to 1.25 inches long—bigger than German roaches but smaller than American roaches. They’re shiny dark brown to almost black, with an oily, greasy look to their bodies.
Wings: Males have short wings that cover about three-quarters of their abdomen. Females have tiny wing pads that are almost useless. Neither sex can fly, so they rely entirely on crawling.
Movement: Compared to German roaches, which are quick and skittish, oriental cockroaches move more slowly. This makes them easier to spot—and squish—but also means they can hide in one spot for longer periods.
Smell: Oriental cockroaches produce a strong, musty odor that’s hard to miss. If you notice a damp, unpleasant smell in your basement or crawl space, it could be a sign of an infestation.
Why the name 'water bug'?
Oriental cockroaches (Blatta orientalis) are often called water bugs because of their strong need for moisture. According to Penn State Extension, they can survive only about two weeks without water but can live up to a month without food. This moisture dependency is why they’re so often found near drains, pipes, and damp areas.
Where Oriental Cockroaches Hide
Understanding where these pests live is the first step in learning how to get rid of oriental cockroaches effectively. They need two things: darkness and moisture.
Indoor Hiding Spots
- Basements and crawl spaces - Their favorite indoor locations because of the humidity
- Around floor drains - They often travel through sewer systems
- Under sinks and around pipes - Anywhere with potential water leaks
- Near water heaters - The moisture and warmth attract them
- Utility rooms - Especially near washing machines and HVAC units
- Behind baseboards - Particularly in rooms with moisture problems
Outdoor Hiding Spots
Oriental cockroaches don’t actually originate inside your home. They live outdoors and come in when conditions are right. Common outdoor harborages include:
- Leaf litter and mulch beds near foundations
- Under landscaping stones and pavers
- In storm drains and sewer manholes
- Around outdoor garbage cans
- In compost piles
- Under porches and decks
Why Oriental Cockroaches Enter Your Home
Oriental cockroaches typically move indoors for a few key reasons:
Seeking moisture during dry spells - When outdoor conditions get too dry, they’ll look for the dampness inside your home.
Escaping extreme temperatures - While they prefer cooler temperatures than other roaches, they’ll come inside when it gets too hot or too cold outside.
Population pressure - When outdoor colonies get crowded, some roaches will migrate to new areas, including your basement.
Following sewer lines - They commonly travel through sewer systems and can enter homes through floor drains, especially in older homes with dry drain traps.
How to Get Rid of Oriental Cockroaches: Step-by-Step
Getting rid of these pests takes a complete approach with several steps. Unlike some pests that respond quickly to a single treatment, oriental cockroaches need ongoing attention because they live in hard-to-reach places.
Step 1: Address Moisture Problems
This is the most important step. Without fixing moisture issues, any treatment you do will only provide temporary relief.
- Fix all plumbing leaks - Even small drips create the humidity oriental cockroaches need
- Use dehumidifiers - Keep basement humidity below 50%
- Improve ventilation - Add vents to crawl spaces and use exhaust fans in bathrooms
- Ensure proper drainage - Grade soil away from your foundation
- Repair leaky gutters - Water pooling near your foundation creates perfect roach habitat
Step 2: Seal Entry Points
Once you’ve addressed moisture, focus on keeping new roaches from getting in:
- Caulk gaps around pipes - Use expanding foam or caulk where pipes enter your home
- Install door sweeps - Especially on basement and garage doors
- Repair foundation cracks - Even small cracks can let roaches in
- Screen vents - Use fine mesh on foundation vents and dryer vents
- Check utility openings - Seal gaps around electrical, cable, and HVAC lines
Step 3: Remove Outdoor Harborage
Reducing outdoor populations means fewer roaches trying to get inside:
- Pull mulch back - Keep mulch at least 12 inches from your foundation
- Remove leaf litter - Clear leaves and debris from around the house
- Store firewood properly - Keep it at least 20 feet from your home
- Clean up organic debris - Remove rotting wood, old cardboard, and other harborages
- Address drainage issues - Fix areas where water pools near the foundation
My Experience with Oriental Roaches in the DC Area
In my experience, German, oriental, and American roaches are very common in the DC metro area. Oriental roaches are especially prevalent in older homes with basements and crawl spaces. I’ve found that the key to long-term control isn’t just treatment—it’s addressing the moisture that attracts them in the first place. One homeowner I worked with had tried multiple DIY treatments with no success. Once we identified and fixed a slow leak under her basement utility sink, the roach population dropped dramatically within weeks.
Step 4: Apply Treatment Products
For DIY treatment, focus on products that work well in damp environments:
Gel baits - Apply in cracks, crevices, and along baseboards where roaches travel. Baits work well because roaches carry the poison back to their hiding spots.
Boric acid dust - Effective in wall voids and behind appliances, but must stay dry to work. Apply lightly—roaches avoid heavy dust piles. Learn more about boric acid for roaches in our detailed guide.
Residual sprays - Non-repellent formulas work best because roaches don’t avoid treated areas. Apply around entry points and along foundation walls.
Insect growth regulators (IGRs) - These prevent immature roaches from developing into breeding adults, helping break the reproductive cycle.
Product Placement Matters
Over-the-counter repellent sprays can actually make oriental cockroach problems worse. These products push roaches deeper into walls and hidden spaces rather than eliminating them. Stick to non-repellent formulas and baits for better results.
Step 5: Monitor and Maintain
Getting rid of oriental cockroaches isn’t a one-time event. You’ll need ongoing monitoring to ensure the population stays down:
- Use sticky traps - Place glue boards near drains, in basements, and around entry points to monitor activity
- Inspect regularly - Check hiding spots monthly for signs of roaches
- Reapply treatments - Baits and dusts may need refreshing every few months
- Maintain moisture control - Keep humidity low year-round
When to Call a Professional
Even with careful monitoring, some situations are best handled by professionals. While DIY methods can handle small populations, there are times when professional help makes sense:
You’re seeing roaches during the day - Oriental cockroaches are nocturnal. If you’re seeing them in daylight, the infestation is likely severe and their hiding spots are overcrowded.
DIY treatments aren’t working - If you’ve tried the steps above for several weeks without improvement, the roaches may be coming from areas you can’t reach, like sewer lines or wall voids.
You have a moisture problem you can’t fix - Sometimes the source of moisture is structural or requires major repairs. A professional can help identify and address these issues.
Health concerns - If anyone in your home has allergies or asthma triggered by cockroach allergens, professional treatment can provide faster relief.
Health Risks from Oriental Cockroaches
According to the American College of Allergy, Asthma & Immunology, cockroach allergens are a significant trigger for asthma, particularly in urban environments. The proteins in roach droppings, shed skins, and saliva can cause allergic reactions and worsen respiratory symptoms. Because oriental cockroaches live in sewers and decaying matter, they can also carry bacteria like Salmonella and E. coli on their bodies.
How Professionals Get Rid of Oriental Cockroaches
When you call a pest control company, here’s what to expect:
Thorough inspection - We look beyond the obvious areas to find entry points, moisture sources, and hidden harborages that DIY inspections often miss.
Targeted treatment - Professional-grade products applied strategically to areas where roaches live and travel. For oriental roaches, this typically includes:
- Non-repellent residual treatments around the foundation
- Dust applications in wall voids and behind appliances
- Bait placements in cracks and crevices
- Drain treatments to address sewer populations
Moisture control recommendations - We identify specific moisture problems contributing to the infestation and recommend solutions.
Follow-up visits - Most oriental roach treatments require 2-3 visits to fully eliminate the population and break the breeding cycle.
At Better Termite & Pest Control, we’ve been handling roach problems in the DC metro area for over 57 years. Our licensed technicians know the specific conditions that cause oriental cockroach issues in Alexandria, Fairfax, Bethesda, and surrounding areas.
Preventing Future Oriental Cockroach Problems
Once you’ve gotten rid of oriental cockroaches, prevention is key to keeping them away:
Maintain low humidity - Keep basement humidity below 50% year-round using dehumidifiers.
Keep drains active - Run water through floor drains weekly to maintain the P-trap seal.
Landscape wisely - Use gravel or stone rather than organic mulch near your foundation.
Schedule regular inspections - Annual pest inspections can catch problems before they become infestations.
Fix leaks promptly - Don’t let small plumbing problems become big roach attractants.
Oriental Cockroaches vs. Other Species
Not sure if you’re dealing with oriental cockroaches or another species? Here’s a quick comparison:
| Feature | Oriental Roach | German Roach | American Roach |
|---|---|---|---|
| Size | 1-1.25 inches | 0.5-0.6 inches | 1.5-2 inches |
| Color | Shiny black/dark brown | Tan/light brown | Reddish-brown |
| Flight | Cannot fly | Cannot fly | Can fly short distances |
| Habitat | Damp basements, drains | Kitchens, bathrooms | Basements, sewers |
| Speed | Slow | Fast | Fast |
Knowing which species you’re dealing with helps you target your treatment. For example, German roaches need kitchen-focused treatment, while oriental roaches require basement and drain treatments. Check out our guide on bugs that look like roaches if you’re unsure what you’re dealing with.
Get Professional Help Today
Oriental cockroaches are persistent pests, but they can be controlled with the right approach. Focus on moisture control, seal entry points, and use appropriate treatment products. If DIY methods aren’t working or you want faster results, professional roach control can make a big difference.
Have questions about oriental cockroaches or need help with an infestation? Call us at 703-683-2000 or email info@bettertermite.com for a free consultation. With over 1,000 five-star reviews and 57 years of experience, we know how to get rid of oriental cockroaches and keep them from coming back.
Frequently Asked Questions
What do oriental cockroaches look like?
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Oriental cockroaches are shiny, dark brown to black, and about 1 to 1.25 inches long. Males have short wings covering about three-quarters of their body, while females have tiny wing stubs. Neither can fly. They have a greasy, oily appearance that sets them apart from other roaches.
Why are oriental cockroaches called water bugs?
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They're called water bugs because they need lots of moisture to survive. You'll usually find them near drains, in damp basements, around leaky pipes, and in crawl spaces. They're strongly attracted to wet, dark areas.
Where do oriental cockroaches hide in homes?
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Oriental cockroaches hide in basements, crawl spaces, around floor drains, under sinks, near water heaters, and in utility rooms. They also live outdoors under mulch, leaf litter, and in storm drains before coming inside.
Can oriental cockroaches fly?
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No, oriental cockroaches cannot fly. Males have short wings and females have only wing stubs, but neither has functional flight wings. They move by crawling and are actually slower than German or American roaches.
How do oriental cockroaches get inside houses?
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They enter through gaps around pipes, cracks in foundations, floor drains, door sweeps, and utility openings. They often travel through sewer systems and can come up through drains during dry weather or when populations are high.
Are oriental cockroaches dangerous to humans?
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Yes, oriental cockroaches carry bacteria like Salmonella and E. coli because they crawl through sewers, garbage, and decaying matter. Their droppings and shed skins can trigger allergies and asthma, especially in children.
How long does it take to get rid of oriental cockroaches?
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With proper treatment and moisture control, you can see improvement within 2-3 weeks. Complete elimination usually takes 4-6 weeks depending on the severity of the infestation. Ongoing prevention is key to keeping them away.
Do DIY methods work on oriental cockroaches?
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DIY methods can help with small populations, but oriental cockroaches are challenging because they live in hard-to-reach areas like wall voids and sewer systems. For established infestations, professional treatment combined with moisture control works best.
What time of year are oriental cockroaches most active?
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Oriental cockroaches are most active from late spring through early fall, with peak activity in May through July. They prefer cooler temperatures than other roaches and may move indoors when outdoor conditions become too hot or dry.
How can I prevent oriental cockroaches from coming back?
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Focus on moisture control by fixing leaks, using dehumidifiers, and ensuring proper drainage. Seal entry points around pipes and foundations. Remove outdoor harborage like leaf litter and mulch near the foundation, and keep floor drains covered or treated.
With five years of hands-on experience in the pest control industry, George Schulz is a registered technician with the Virginia Pest Management Association and a proud third-generation professional in a family business that's been protecting homes for over 57 years. He manages and trains a team of service pros while also leading internal research efforts—recently spearheading a deep-dive review of thousands of documents on pest control materials to hand-pick the most kid and pet friendly, most effective solutions tailored specifically for homes in the DC metro area.