Mouse-Proofing an Older Shelton Home Before Fall

Every fall, once the nights in Shelton drop into the 40s, mice start looking for somewhere warm to spend the winter. Older homes make it easy for them. Fieldstone foundations, settled sills and decades of pipe and wire holes add up to a lot of doors nobody meant to leave open.

The work isn't complicated: find the gaps, seal them with something mice can't chew, and take away the food and shelter, all before the cold nights arrive. August is the time to do it. What follows is the walk-around we'd suggest for an older house, what to seal it with, and how to clean up safely if they've already beaten you to it.

A flashlight walk in August

Take a flashlight and walk around the house slowly. A mouse can squeeze through a gap about the width of a pencil, so small openings count. Watch the sunny walls while you're out there, because the same gaps that let mice in also let stink bugs and cluster flies into the attic, and one round of sealing helps with both.

A rough timeline works well. Early August, walk the outside and list every gap. Mid-August, buy the mesh, sealant, flashing and new door sweeps. Late August, seal the outside openings and the sill line. Early September, check the attic and garage, set a few snap traps where kids and pets can't reach them and watch for fresh droppings.

• Gaps between foundation stones where the mortar has crumbled
• The space where the wood sill sits on the foundation
• Holes around pipes, the dryer vent, AC lines and cable wires
• Worn or missing garage door seals
• Bulkhead doors and cellar windows that don't close tight

From the sill line to the attic

Inside, look along the top of the foundation wall where the floor joists sit. That sill line is a highway for mice in a lot of Shelton homes, especially colonials and capes on fieldstone or block. Check behind the furnace, around the water heater and in the corners where stored boxes lean against the wall. Up in the attic, look for droppings on top of the insulation, shredded paper and little tunnels through loose fill. Mice climb inside the walls, so an attic problem can easily start at a gap in the basement.

This applies to most of the older houses around here. Huntington's historic colonials often have fieldstone foundations with a couple of centuries of settling behind them. Mill-era two-families in Ansonia add shared basements and open pipe runs between units. The steps are the same everywhere. The number of gaps is what changes.

Steel mesh, mortar and a new door sweep

Mice chew through foam, rubber and wood, so use materials they can't. Pack steel or copper mesh into the gaps and cover it with mortar, caulk or sealant. Use metal flashing or hardware cloth over larger openings, and replace worn door sweeps and garage seals. Spray foam on its own won't stop them.

For a fieldstone wall with a lot of open joints, repointing the mortar is a bigger job for a mason, and a pest tech can point out the worst spots first. Some homeowners have that done as part of a seasonal service schedule. Meanwhile, store birdseed, grass seed and pet food in metal or heavy plastic bins, keep firewood off the ground and away from the house, and clear clutter from the basement walls so you can see what's happening. Mice in the stone walls also feed young ticks, which is one reason a tick treatment along the walls pairs well with sealing the house.

To speak with someone about your home, telephone (203) 953-7616.

If they've already moved in

Don't sweep or vacuum dry droppings. Wear gloves, air the room out, and wet the droppings and nest material with disinfectant or a bleach solution. Let it soak, wipe it up with paper towels, bag it and throw it out. Never scatter loose poison. If bait is used, it belongs in locked, tamper-resistant stations placed by a licensed tech.

If you're still catching mice after the sealing is done, there's a gap somewhere you haven't found, and that's a sensible time to have a mouse exterminator who traps and seals take a look.

See also: Mouse and Rat Control, General Pest Control, Stink Bugs and Fall Invaders