Do you hear the little pitter patter of mice in your crawlspace? Have you seen droppings when you've gone into that area? If you've answered yes to either of these questions, it's time to think about mouse-proofing your crawl space. Luckily, there's lots of solutions that can help.
1. Eliminate Current Populations
Mice are extremely active breeders. Mice are only pregnant for three weeks, and they give birth to litters with anywhere from three to over a dozen baby mice. Those mice, in turn, can get pregnant by their sixth week of life.
If you have a mouse problem, it will only get worse in most cases, due to their abundant breeding habits. To get matters under control, work on eliminating your mouse population. Sticky traps, snap traps baited with peanut butter, and poison are all options to try.
2. Seal the Cracks
In addition to setting traps and putting out poison, you need to seal potential entries into your crawl space. In many cases, you can see the entries that the mice are using around the outside of your foundation. Find all the cracks and small holes that you can.
Then, rip or cut a small piece of steel wool and put that in the hole or crack. Complete the patch using expanding foam. The metal prevents the mice from eating the foam. If you have a lot of termites in the area, you should keep the foam and use a latex caulk designed to stand up to exterior usage — don't just use the caulk that you use around your bathtub. This can also help in places with carpenter ants.
3. Remember to Check the Base of the Foundation
In some cases, mice may have burrowed through dirt and entered your crawlspace through a crack or hole that isn't visible. To find these areas, you need to crawl around your home, methodically removing dirt from around the foundation. Dig to a depth roughly equal to the length of your hand. Then, look for entries, and seal them as explained above.
4. Consider Waterproofing the Crawlspace
Any measures that seal your crawl space from the outside will help to reduce your mice population. Because of that, you may want to consider waterproofing the crawlspace. This process usually needs to be done by a professional, and in addition to keeping out mice, it also protects your possessions from flooding or damage.
5. Remove the Temptations
Mice need a reason to go into a crawlspace. They are opportunistic, and in most cases, they won't just hang out in an empty crawlspace. Instead, they tend to target crawl spaces with lots of food or other opportunities.
If you store potatoes, onions, or similar dry store foods in your crawlspace, find another spot for them, or make sure that they are stored in airtight, covered barrels. Even if there's not food in your crawl space, you may want to look for and get rid of items that mice may mistake as food. For example, popcorn strings for Christmas trees and kids' art projects featuring dried noodles or hardened edible clay both fall into this category.
6. Seal the Entry Door
In rare cases, you may have an external door leading to your crawl space. Consider adding extra sealing to that door. Weather striping along the edges of the door can help. Also, you can make a custom door sealer by squirting a bit of caulk into the corners of the door.
Then, place wax paper over the caulk and close the door. The door will push the caulk into the right spot. When it dries, remove the wax paper and enjoy your newly sealed door.
For more tips on keeping rodents out of your crawlspace, contact a professional who specializes in crawl space pest control.