Symptoms
- Roaches seen near the sink, tub, or toilet, especially at night
- Small dark droppings along baseboards or in cabinets
- Roaches appearing to come from a drain
Likely causes
- CommonMoisture from condensation, a leak, or standing waterBathrooms offer reliable water access that roaches seek out even without food nearby.
- CommonEntry through gaps around plumbing penetrationsPipes under the sink or behind the toilet often have gaps large enough for roaches to pass through from a wall void or crawl space.
- PossibleDrain access, especially in older or dry-trap plumbingA drain that's rarely used and has dried out can lose its water seal, letting roaches travel up through the pipe.
What to do
- Run water in rarely used drains, like a guest bathroom or basement floor drain, periodically to keep the trap sealed against pests.
- Fix any leaks or condensation issues contributing to dampness in the bathroom.
- Seal gaps around pipes under the sink and behind the toilet with caulk or an appropriate escutcheon plate.
- Clean the bathroom thoroughly, including behind and under fixtures where roaches like to hide.
- Place gel bait or bait stations in cabinet corners and behind fixtures rather than relying only on sprays.
- Reduce clutter under the sink, which gives roaches fewer places to hide undisturbed.
- Call a pest control professional if activity continues, since a plumbing-connected infestation can be harder to fully resolve on your own.
Tools and parts
- Caulk gun
- Cleaning supplies
Roach bait gelSearch: “roach bait gel”
When to call a pro
Call a plumber for a leak and a pest control professional if roaches continue after cleaning and sealing.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.