Crawl Space Rodents in Asheville: Rats and Mice

In Asheville, the rodents that give homeowners the most trouble come from below, not above. Norway rats and house mice move into the crawl space, and from there into the walls and floors of the house. Roof rats, the attic climbers people worry about in warmer, lower places, are uncommon at Asheville's elevation, so this guide stays with the two that actually show up here. If the noise is low and near the floor, and you have an older home, read on.

Why old Asheville homes are a target

Much of Asheville's housing dates to the early 1900s, and the bungalows in Montford, West Asheville, Kenilworth, and Grove Park sit on pier-and-beam crawl spaces and stone or rubble foundations. Over a century those foundations settle, and small gaps open at the base of the wall, at the vents, and where pipes run through. Norway rats are strong, low-living rodents that burrow near the foundation and push through those gaps into the dark, sheltered crawl space. House mice follow the same routes, and they press indoors hardest once the first cold mountain nights arrive in the fall. For a neutral overview of rats and mice and how to manage them, the EPA's guidance on managing rodents in your home is a useful reference.

How they get into the crawl space

Rodents reach the crawl space of an older Asheville home through:

• Settled foundation gaps. Stone and rubble foundations shift over time, and the gaps that open at the base of the wall are an open door for a Norway rat.
• Crawl-space vents. Unscreened or broken foundation vents let rats and mice walk right in.
• Utility penetrations. The spots where water lines, gas lines, and wiring pass through the foundation are common entry points.
• Torn access doors. A warped or gnawed crawl-space access door leaves a gap at the corner.

Once inside, a Norway rat only needs a gap about the size of a quarter to keep coming and going, and a mouse needs one the width of a pencil.

Signs of crawl space rodents

Because they live low, the signs are low too. Listen for scratching, gnawing, or scurrying near the floor or in the lower walls at night. Look for droppings in the crawl space, capsule-shaped and larger than mouse droppings for Norway rats, and rice-grain droppings for mice. You may also find burrow holes in the soil near the foundation, greasy rub marks along the base of the wall, gnawed pipe insulation and wiring, and a musky smell rising from the vents. On wooded lots around Candler and Weaverville, deer and white-footed mice may nest in a crawl space or shed as well, and their droppings call for careful, safe cleanup because they can carry hantavirus.

How to get them out and keep them out

Crawl space rodent control works from the foundation up, and it takes three things together:

• Remove the population. Trapping in the crawl space and along the runways the rats use, with follow-up until the activity stops.
• Seal the foundation. Exclusion closes the settled stone-foundation gaps, the vents, and the utility penetrations with rodent-proof, metal-backed materials so they cannot get back in.
• Clean up what they left. Cleanup removes the droppings, the fouled insulation, and the scent trails that would draw the next colony in.

Start with an inspection so the entry points and burrow routes get mapped before any work begins. If your home is in an older part of town, our West Asheville rodent control page covers the same bungalow-and-crawl-space problem block by block. The heavier lifting of removal and sealing is best left to a local rodent exterminator who works these foundations often.

Crawl space rodent questions