Your crawlspace is a necessary section of your home, even if you never venture into it yourself. It must remain somewhat open so that moisture doesn't collect and also so workers can access the plumbing, electrical lines, or ductwork that runs through it. Unfortunately, mice also sometimes get access to the crawlspace. The following tips can help you keep them out.

Tip #1: Install a vapor barrier

A vapor barrier laid over the soil in the crawlspace serves several purposes. First and foremost, it prevents ground moisture from collecting in the crawlspace. This cuts down on moisture-related damage as well as ensuring there is no water source for visiting rodents. Most mice won't stick around if they don't have any access to water. Second of all, it makes it difficult to burrow into the soil. This means ground dwelling rodents won't be attracted to the space.

Tip #2: Remove any food sources

After water, the next major attractant for mice is food. If your floors are properly installed with solid sheathing beneath, food should never trickle down from above. Most homes also have a vapor barrier installed on the underside of the floor sheathing as well, which also prevents crumbs from penetrating – although you will need to make sure it isn't torn or damaged. Finally, don't plant anything around the crawlspace that could provide food, such as berry bushes or seed-producing plants like sunflowers.

Tip #3: Seal the sides

Sealing the sides against rodent invasion must be done carefully since air still must circulate freely beneath the house. Lattice is commonly used, but the openings are large enough to still allow rodents in. You can back the lattice with a tight wire mesh. The opening need to be less than 1/4 inch in size, since small mice can squeeze through such an opening. Also, use metal mesh since the mice won't be able to chew through it. Once the panels are installed, seal any gaps with more mesh or caulk so mice can't squeeze through.

Tip #4: Cut off indoor entry points

Sometimes mice access a crawlspace from inside the home. This is most often through holes in baseboards or via the walls. Fill in any gaps, such as around outlet boxes, with spray foam insulation or mesh. Cracks in baseboards and floorboards must be repaired with a patch or caulk. The fewer entries into the walls in the home, the less likely that the mice will find their way to the crawlspace.

Contact a crawlspace pest control expert is you suspect that there may be rodents in your crawlspace. They can help you to eradicate them in the safest ways possible.