Mice in Crawl Space

How to Remove Mice in Your Crawl Space

Mice are experts at finding ways into homes. They need only the smallest gaps in walls to sneak inside, so crawl spaces offer easy access. Many wires run from the outdoors into the area under the first floor of buildings.

There are many reasons homeowners find mice hiding in crawl spaces. The pests enjoy an undisturbed place to nest and give birth, and these areas also protect rodents from predators and the weather.

Problems with Mice in the Crawl Space

Mice in the crawl space can damage some of the most sensitive parts of your house and increase the risk of diseases. Since people generally don’t go into the crawl space, the pests can stay concealed for long periods of time.

Mouse Damage

Mice chew wood, plastic, siding, electrical wires, carpet, fabrics, clothing, mesh, and some thin metals. In the crawlspace, mice gnaw on pipes, wires, and insulation. This gnawing damage can decrease energy efficiency, cause water leaks, and increase the risk of electrical fires!

Mice constantly search for food and will access your home’s living space in search of a food source. They can gnaw on baseboards and structural beams, cabinets, pipes, vents, rugs, drywall, cardboard, and storage containers. Their behaviors can cause power outages, heating and cooling system failures, and broken water lines.

Contamination from Mice

Mice contaminate your living space by leaving droppings and urine wherever they travel. Mouse feces are known to host mold spores that humans should not inhale. If living in your wall or ceiling, urine and feces can seep through, creating ugly stains.

Diseases from Mice

Diseases mice carry often have long-term effects on people and may even be fatal. Residents should be aware of the bacterial and viral infections linked to mice, such as:

• Leptospirosis – This illness spreads through food or water tainted with mouse feces.
• Plague – While extremely rare, a bite from a flea or rodent infected with the bacteria can transfer plague.
• Salmonellosis – The pests spread this mouse disease through contact with food and kitchen surfaces. Their urine and saliva carry the pathogen that causes infection.
• Hantavirus – Deer mice are the main vectors of this illness. Once inhaled, airborne particles from their feces transmit the virus.

In addition, mice can spread diseases associated with the ticks, fleas, and other parasites they carry. Residents in mouse-infested homes may be at risk for tick fevers and Lyme disease.

In addition, trapped rodents often die in crawl spaces. Their carcasses then release odors into homes, attracting insects like cockroaches and flies.

How Do Mice Get into the Crawlspace?

Mice can squeeze through a gap around the size of a pencil.

🏠 Common Mouse Entry Points into Crawlspaces:

1. Gaps Around HVAC or Plumbing Penetrations
   • Mice can squeeze through openings where pipes or ducts enter the crawlspace.
2. Vents with Damaged or Missing Screens
   • Crawlspace vents often have screens that can become torn or corroded, making an easy entry point.
3. Gaps Between Siding and Foundation
   • Poorly sealed transitions between siding and the foundation wall can create mouse-sized gaps.
4. Unsealed Access Doors or Hatches
   • Crawlspace doors that don’t seal tightly or have deteriorated framing invite rodent intrusion.
5. Brick Weep Holes Without Rodent Guards
   • These are intentional gaps in brick veneer for ventilation and drainage—perfect for mouse access if unprotected.
6. Cracks in Foundation Walls
   • Even small cracks or gaps (as little as ¼ inch) can be exploited by rodents.
7. Utility Conduits or Electrical Lines
   • Entry points where wiring enters the home are frequently overlooked and rarely sealed well.
8. Under Siding Overhangs or Corner Trim
   • Gaps where siding meets trim boards or overhangs often serve as concealed entryways.
9. Broken or Missing Crawlspace Skirting (in pier-and-beam homes)
   • Especially common in manufactured or raised homes, missing skirting makes it wide open for rodents.
10. Rodent-gnawed Openings

If mice have entered before, they may have chewed their way in through wood or soft materials.

Watch a Mouse Inspection

How to Get Rid of Mice from a Crawl Space

When homeowners identify a mouse infestation, they should call pest control professionals immediately. Once a mouse finds a safe place for shelter with a readily available food source, it will not leave. In fact, mice breed rapidly, and an infestation can grow into a huge mouse problem.

Critter Control technicians have experience with these issues. They can safely and efficiently trap mice and remove them from a crawl space. Once the infestation is under control, we install exclusions around the foundation of your house to keep rodents out. Finally, our repairs can include sanitization agents, crawl space encapsulation, and vapor barriers.