How to Keep Mice Out of Duct Work and Crawl Spaces

Lee Weal

In search of food and shelter, rodents will enter a home any way they can, exposing your family to germs and disease. Dark, hidden places, like duct work and crawl spaces, offer the perfect environment for mice to breed and travel throughout the home. Getting rid of these pests is a two-step process.

Keep mice out of your home.

The first step is to make your home as impenetrable as possible against rodents. The second step is to kill the mice in the area to prevent an infestation from occurring.


Avoid using poisons. The mice may die inside of the duct work or crawlspace, creating an offensive odor, and you may need to consult a professional to remove the dead rodent.

  1. Seal off any entry points. Mice can squeeze into spaces as small as 1/2-inch. Walk around the exterior of your home and look for all areas that are vulnerable. Attach wire mesh or hardware cloth to duct openings and secure it with wire or duct tape.

  2. Repair any holes and cracks where the home's foundation meets the ground with concrete patching material.

  3. Cover the crawlspace with wire mesh or hardware cloth. This treatment will allow air to flow through while keeping rodents out as they cannot chew through metal.

  4. Bait wooden mouse traps with peanut butter and place them close to exterior walls where mice are likely to travel. Alternatively, use glue traps. Space traps about 10 feet apart. Check them frequently and re-bait as needed.

  5. Eliminate grass or bushes close to the home's foundation or cut it back. Rodents prefer to travel along walls under the cover of thick vegetation.