Can mice climb brick walls?
Mice can climb brick walls and chimneys and enter any small opening.
Ignoring the sound of the mice scurrying across your ceiling drywall does not make them disappear. One pair of breeding mice produces as many as 10 litters a year. Mice chew through insulation, paper goods and stored clothing to harvest nesting materials. Constantly growing teeth stimulate the gnawing that can damage electrical wiring and cause fires. Any opening dime-size or larger gives mice access to your home. Mice in the walls find easy routes to the attic. Mouse-proof your house first, then eliminate the mice inside to effectively resolve your pest problem.
Mouseproofing the House
Look for holes and gaps on the exterior lower level of your house first. Check around pipes, conduits, coaxial cables and dryer vents for any unsealed openings. Inspect the joint between foundation sills and walls and the framing of foundation vents and any basement windows.
Inspect window and door framing and check the eaves as well as the flashing around attic vents, chimneys and fans on the roof.
Fill gaps of 1/2-inch width or less by running a bead of exterior-grade caulking along the gap with the caulking gun. Fill any gap 1/4 inch or wider with the caulk.
Pack coarse stainless steel wool into larger gaps, pressing the steel wool firmly into place with the flat-head screwdriver.
Run a thick bead of exterior-grade caulking over the steel wool to seal the packed gap.
Patch large holes or rotted areas temporarily with pieces of metal roof flashing. Cut a piece of flashing with the tin snips, at least 2 inches larger than the damage. Screw the flashing to the damaged area with the screwdriver and sheet metal screws.
Look in the attic for urine-stained areas and trails of mouse droppings, small black pellets the size of rice grains. Mice choose secluded areas in eaves and corners and beneath mats of insulation for nesting sites, and travel beside ceiling joists and walls for extra protection.
Set snap traps along the mouse trails. Along ceiling joists, set two traps side by side, with baits at opposite ends, putting bait in front of mice traveling either direction. When using a single trap, place the baited end against the joist.
Set traps inside any drop ceilings and at points, like plumbing and heating penetrations, where mice can exit the ceiling in the same way as in Step 2. Set traps inside a void between ceiling joists as necessary.
Check traps daily to dispose of bodies and refresh any old or missing baits. Handle the traps with rubber gloves, since mice corpses might carry disease organisms. Snap traps offer the best chance of removing mice from the ceiling. Poison baits eliminate the mice, but the mice might expire in walls or tight spaces where you can't remove the bodies.