Rats in the Crawl Space: What to Check and What to Expect

The crawl space is the part of a Beaverton house people check the least and rats like the most. It's dark, it stays out of the rain, and it's full of soft insulation. These are the signs to watch for and what to expect once you call.

Signs From Inside the House

Listen and sniff first:

• Scratching or thumping under the floor at night
• A musty or ammonia smell in a closet, bathroom or the furnace area
• Pets sniffing at floor vents or one particular spot
• Droppings near the crawl space hatch or the furnace

Signs From Outside

Then walk the foundation:

• Vent screens that are torn, bent or pushed in
• Burrows along the foundation or under the deck
• Rub marks around a vent or pipe opening
• Gaps where the sewer or water line leaves the house

If You Look Yourself

Wear old clothes, gloves, eye protection and a dust mask, and bring a bright flashlight. Look from the hatch first. You're checking for droppings on the vapor barrier, insulation hanging from the floor joists, nests, and tunnels or holes in the dirt. Don't crawl through droppings or stir up dust. If you see a lot, back out and let the provider handle it.

What Happens Next

The usual order is trap, seal, then clean. Sealing comes before cleanup so new rats can't follow the old ones in. Crawl space cleanup covers the last step, and rodent exclusion covers the sealing.

See also: Crawl Space Cleanup, Rodent Inspection, Rodent Exclusion