4 Ways to Keep Rodents Out of Your Crawl Space

1 March 2017
 Categories: Construction & Contractors, Articles


If you've noticed rodents in or around your home, and you have a crawl space, this could very well be their main entry point. Rest assured that keeping them out isn't too much of a challenge, so long as you know what to do. Here are four easy measures you can take to keep your crawl space—and your home—free of rats and mice.

Seal Openings

Rats and mice can squeeze through extremely small openings, but there isn't a universal measurement that works as a cutoff for all rodents. In other words, the belief that mice can squeeze through a hole the size of a pencil is pretty much a myth. The general rule of thumb is this: if they can fit their head in, the rest of their body will easily follow.

This doesn't mean you need to run around your yard chasing rodents with a measuring tape. What you can do is investigate your crawl space for the main entry points. This includes tunnels or holes under the wall, cracks in the corners, and unsealed spaces between doors and the wall. Contrary to popular belief, you really don't need a ventilated crawl space. In fact, it should be as airtight as possible.

Seal cracks and openings in the wall with caulk or expanding foam, and place weather stripping around the door to your crawl space. If you discover tunnels under the wall, fill them in with soil and pack it tightly, rechecking the area regularly afterwards for disturbances.

Lay Down Plastic Sheeting

Rats and mice need ample water and food as well as a moist environment in which to live. So minimizing the amount of moisture in your crawl space can reduce the likelihood of rodents claiming your home as their own.

To accomplish this, lay down wall-to-wall plastic sheeting in your crawl space. Use bricks or large rocks in the corners to hold the plastic in place. This will not only help keep the critters out, but it can also prevent the growth of mold and mildew.

Monitor the Bushes

If you have bushes or a lot of brush around the perimeter of your home, you should be aware that they provide the perfect habitat for rodents. They offer shade, shelter, and soft soil for rats and mice to hide in before digging their way under the walls and into your crawl space.

You may not want to dig up your bushes and plants, but be sure to monitor the area regularly for critters. If you're planning to plant new greenery, consider strategically putting enough space between your home and the plants so the soil around your crawl space is more exposed and, therefore, less attractive to small animals.

Use Humane Repellents and Traps

Rat poison is an option, but it's potentially dangerous in a number of ways. First, other pets or small children may accidentally ingest it. Also, pets can become sick or die if they eat a rodent that's consumed rat poison. Here are a couple of safe and humane alternatives you can use around the crawl space and any other entry points to your home. 

  • Moth balls: Be sure to distribute moth balls in areas where children and pets cannot access them, such as in the corners and other areas where the rodents are entering.
  • Humane traps: These plastic, box-like cubes can be used—with the help of a little peanut butter or cheese—to lure unsuspecting rodents. Once inside the cube, the "trapdoor" closes. 
  • Natural deterrents: There are a number of products available on the market that are safe to use and are great at repelling rodents, such as peppermint oil, pepper spray, and cloves.

To learn more, contact services that provide pest control and crawl space repair services.