Leaks, humidity and pests in San Antonio
Updated October 27, 2026.
San Antonio is humid much of the year. Water is what many household pests need most, so leaks and damp spots are where problems start.
Why leaks bring roaches (and other pests)
Roaches need water. UC IPM says they hide by day in warm, dark, moist spots such as crawl spaces and around water heaters, and it lists fixing plumbing leaks as a basic control step. Its advice is plain: pesticides alone won't solve a roach problem. If a drip under the sink stays, so does the reason roaches are there. Other household pests follow damp too:
- Silverfish: live in damp, warm places like laundry rooms. UC IPM: repair plumbing leaks and drips, and dehumidifiers in closed spaces help. [UC IPM]
- Centipedes: show up indoors in damp basements, closets and bathrooms. [UC IPM]
- Drain flies: breed in the slime inside sink and shower drains. UC IPM says getting rid of that breeding site is the key, so clean the drain. [UC IPM]
- Carpenter ants: come inside looking for moisture, and their nests often start in wood damaged by water or decay. UC IPM: fix leaky pipes and add ventilation to damp attics and subfloors. [UC IPM]
- Subterranean termites: need moist conditions, and UC IPM lists getting rid of excess moisture as part of managing them. [UC IPM]
UC IPM's prevention guide for property managers names the water sources to check: plumbing leaks, condensation from refrigerators or air conditioning, and standing water. [UC IPM]
Got a drip under the sink or a pipe that sweats? We can find and fix the leak, which takes away the water that keeps pests around.