A Rodent-Proofing Checklist to Finish Before Winter.

Stand back from the house and look at the roof edge. You are looking for loose or missing boards, gaps at the soffit and fascia, damaged vent covers and places where the roof meets a wall. Moss and debris can hide gaps, so look closely.

• Soffit and fascia boards that are soft, loose or pulled away.
• Attic vents with torn or missing screens.
• Gaps where the roof meets a wall or chimney.
• Branches within a few feet of the roof.
• Gutters packed with debris that can hold water against trim.

Do not work on a steep roof or at a height you are not comfortable with. Ask a roofer or a handyman for the repair, and tell them why.

Walk the base of the house and check every spot where a pipe, wire, cable or vent goes through the wall. Many have a gap around them, and a quarter-inch gap is enough for a mouse. Look at the dryer vent, the bath fan vent and the hose bib.

Fill small gaps with a sealant suited to the material and stuff copper mesh into larger ones before sealing. Steel wool alone rusts in wet air. For larger or more complicated gaps, see rodent exclusion for how a professional approaches them.

Check each foundation vent. Torn or rusted screens are common. Replace them with stainless mesh, and make sure the cover fits tightly. Check the access door for a good seal and a latch that works.

Look for cracks in the foundation and gaps where the siding meets the concrete. Mortar or masonry-grade sealant fills small gaps. See crawl space rodents in wet winters for more on this area.

The garage door seal is the first thing to check. A seal that has flattened or torn leaves a gap along the slab. Replacing it is a quick job and one of the most effective. Check the corners where the door meets the wall, and the base of any side door.

Inside, pull boxes a few inches away from the walls, and move bulk food, pet food and seed into sealed metal or hard plastic bins. Cardboard boxes are nest material, so store bedding and holiday items in lidded totes.

Move woodpiles away from the house and off the ground. Trim shrubs back from the foundation. Clean up fallen fruit and nuts. Check that compost and trash bins close tightly, and take bird feeders in at night if you see activity.

If you have a shed or coop, give it the same treatment as the house, with metal feed bins, hardware cloth and a clear space beneath.

Put pantry food in glass, metal or hard plastic containers. Clean up crumbs and spills, especially under appliances. Do not leave pet food out overnight. Check under sinks for gaps around pipes, and close them with copper mesh and sealant.

Listen at night for the first signs. Light scratching, a rustle in a cabinet or a few droppings are early warnings. Do not sweep dry droppings. Photograph them, and call.

• Stainless mesh or hardware cloth and tin snips.
• Copper mesh and a masonry-grade sealant.
• A replacement garage door bottom seal.
• A strong flashlight and a ladder.
• Gloves, a mask and eye protection.

Buy the materials once and keep the extras. A small stock of mesh and sealant lets you fix a gap the moment you see it, which is much better than meaning to do it later.

Start with the biggest gaps and the places closest to food, such as the garage and kitchen walls. Move to the crawl space and roof edge, which take more time. Finish with the yard. If you run out of time, the garage door seal and the crawl space vents are the two highest-value jobs.

If you have already heard or seen activity, sealing first can trap animals inside. Call and describe what you found, and we will tell you the right order. See our rodent inspection page for how a visit works. Otherwise, finishing this list before the rain gives you a head start.