Let me tell you about crawl spaces.
Most homeowners never go in them. Some homeowners don't even know they have one. That lack of attention is exactly why they become problems. In the pest control business, we have a saying: if you want to know what's really going on with a structure, you check underneath it.
The Practical Case
Crawl spaces are ideal habitats for rodents, insects, and moisture-loving pests. They provide shelter, warmth, darkness, and proximity to the structure's plumbing and electrical runs. Rats will nest under a house for years before showing up in the living space. Termites often establish colonies in crawl space wood before you see a single swarm.
Standard moisture levels in a crawl space should be below sixty percent humidity. Most of the ones I inspect run higher than that. Moisture attracts pests. It's that simple and that consequential.
Vapor barriers help. Ventilation helps. Access panels that seal properly help. Very few homes have all three in good condition.
The Less Practical Case
In 1991, I was running a standard residential treatment at a property in Alvarado, Texas. Routine job. Ants in the kitchen, some roaches near the water heater. The homeowner mentioned they'd been hearing sounds under the house.
I went in with a flashlight and a respirator.
I found the pest problem. I also found some other things. I'm not at liberty to discuss the other things. What I can say is that I have checked every crawl space on every job I've taken since then, and I have never regretted doing so.
What I Look For
When I go into a crawl space, I'm checking for:
- Active pest activity (droppings, nesting material, runways) - Moisture damage and standing water - Vapor barrier condition - Wood deterioration consistent with fungal or insect damage - Entry points from the exterior - Anything else that needs to be documented
I take notes. I take photos. I keep files. Some of those files go back to 1992 and I have never thrown any of them away.
If your current exterminator doesn't check the crawl space, ask yourself why.
Then call me.
— D. Gribble
About the Author
Dave Gribble has been in the pest control business since 1992. He lives in Texas. He works alone, by preference. He does not have social media accounts, which he considers a security feature.