Exclusion Guide

Mouse-Proofing Your Waco Home Before Winter: A Room-by-Room Checklist

October's first cold snap triggers the annual house mouse movement into Waco structures. A September gap audit — going room by room through the entry points mice actually use — closes those gaps before the pressure event rather than treating the resulting infestation after it. Here's the practical checklist.

Why September Is the Right Month for This Checklist

Mice are still outside in September — in landscaping, garden borders, adjacent fields, and the brush margins around Waco properties. The gaps you seal in September are sealed before any mice are inside. The gaps you discover in November are gaps that already have mice in the kitchen.

The inspection is free if you call us; the exclusion work is quoted before we start. But if you want to do a preliminary self-assessment before calling, this checklist identifies the locations and signs worth looking for.

One important note before starting: any gap a pencil fits through is a gap a mouse can fit through. The 1/4-inch standard is real. If you're assessing your home and dismissing small gaps as too small to matter, you're likely missing the primary entry points.

Exterior — Start Outside Before Going Room-by-Room Inside

Weep Holes (Brick Veneer Homes)

Look for the open gaps in the bottom course of brick along the exterior wall — these are intentional drainage openings called weep holes. On homes built before 2005, the plastic inserts that originally covered these holes are often degraded, missing, or pushed out. On homes without covers at all, you're looking at open 1-inch rectangular gaps at grade level — direct mouse entry points. Proper fix: 1/4-inch hardware cloth cut and secured over each opening, not filling with caulk or mortar (these must remain open for wall drainage).

A/C Line-Set Penetration

Find where your air conditioning refrigerant lines, electrical conduit, and drain line enter the exterior wall — usually on the side of the house closest to the outdoor condensing unit. Look at the gap around the bundle where it passes through the wall. On most homes there's a foam boot or flashing here, but there's almost always a gap remaining around the bundle. Stuff copper mesh into that gap and apply polyurethane caulk over the face. This is one of the two most consistent mouse entry points in Waco homes.

Dryer Vent Cover

Look at the exterior dryer exhaust vent — usually a louvered flap on the side of the house. Check whether the flap opens and closes freely or whether it's broken, stuck open, or missing entirely. A dryer vent cover with a broken flap is a direct mouse entry into the duct run and from there into the wall cavity or utility room. Replace broken flap covers with spring-loaded aluminum or caged covers — they're inexpensive and prevent mouse access.

Garage Door Threshold and Sides

Close your garage door and look at the threshold — the seal where the door meets the concrete floor. Is there a gap you can see light through? Corner gaps are especially common as rubber threshold seals compress and pull over time. Side clearances on the door itself are a secondary check — look at the gap between the door panel and the vertical side frame when the door is closed. Any gap wider than 1/4 inch is addressable with threshold seal replacement or side-gap weather stripping.

Foundation Perimeter Cracks

Walk the perimeter of the foundation — particularly any pier-and-beam properties with exposed skirting or foundation walls. Look for cracks wider than 1/4 inch, gaps where skirting has pulled away from the foundation, and any open vent screens. Foundation cracks at grade get hydraulic cement; skirting gaps get hardware cloth or wood repair; degraded vent screens get hardware cloth replacement.

Kitchen — Highest-Risk Interior Room

Under the Sink Cabinet Base

Open the cabinet under the kitchen sink. Look at where the drain pipes and supply lines pass through the cabinet floor and back wall. There is almost always a gap around these penetrations — often a large one where the pipes were routed through the cabinet without sealing. This is the most common location for mouse entry into kitchen cabinetry. Pack copper mesh into the gap and apply polyurethane caulk.

Cabinet Toe-Kick Gaps

Look at the gap between the base of the kitchen cabinets and the floor — the toe-kick area. In homes where mice have been present previously, this gap often has grease smear marks at the base corners where mice travel between cabinet interior and wall cavities. Any gap at the cabinet-wall junction behind the toe-kick is addressable with copper mesh and caulk.

Dishwasher Utility Penetrations

Look at the gap behind and beside the dishwasher where the water supply and drain connections pass through the cabinet. These are often overlooked penetrations that were never sealed at installation.

Laundry Room / Utility Room

Washer and Dryer Connections

Look at the gap where the washer water supply lines and drain hose pass through the wall. Same assessment as the kitchen sink — almost always a gap that's never been sealed. Copper mesh plus caulk.

Gas Line Penetrations

Where the gas line enters the home — typically through an exterior wall near the dryer or water heater — there's usually a gap around the pipe that was never sealed at installation. This is also a potential gas-leak-detection issue independent of rodents; if the penetration is completely open and you can feel air movement, note that separately from the rodent exclusion concern.

Water Heater Closet

If your water heater is in an interior closet, look at the bottom of the closet walls for any penetrations. Water heater closets frequently have gaps at the base where the space connects to adjacent wall cavities — particularly in mid-century Waco homes where the water heater closet was added during a renovation rather than built as original construction.

Garage

House-to-Garage Door Threshold

The door between the attached garage and the living space is a frequently overlooked entry point. Check the threshold seal on this door just as you would an exterior door — it's the last line of defense if mice enter the garage but haven't yet reached the living space.

Attic Access Hatch

If your garage has an attic access hatch in the ceiling, check whether the hatch seals fully when closed. Gaps at the hatch perimeter allow mice to move freely between attic and garage — and if mice have found their way into the garage, the attic access is a pathway to the rest of the structure.

Stored Cardboard Boxes

This isn't an exclusion point, but it's relevant: mice prefer cardboard as nesting material. If you have long-term storage in cardboard boxes in the garage, those boxes are both preferred nesting sites and evidence repositories — mice shred them for nesting and leave droppings on and inside them. Transition long-term storage to sealed plastic bins.

Attic Access Check (Brief)

You don't need to fully enter the attic for a preliminary assessment. Open the attic access hatch and hold a flashlight at the opening. Look for:

• Droppings visible near the hatch opening or on top of insulation
• Insulation displacement or nesting material visible in attic corners
• Any obvious light visible through gable vents (indicating no hardware cloth behind the louvers)

If you see any of these, schedule a professional inspection. Attic rodent work is beyond DIY scope for most homeowners — the PPE requirement and the difficulty of accurate trap placement in attic spaces make professional involvement the right call for any attic evidence.

A note on attic evidence cleanup: The CDC recommends against vacuuming or dry-sweeping rodent droppings, as these methods aerosolize hantavirus particles from dried fecal material. In enclosed spaces like attics, this creates a respiratory hazard. The correct protocol — wet disinfectant application before physical removal, followed by HEPA-filtered removal — is not a consumer-grade task. If your attic walkthrough finds droppings or nesting material, professional cleanup is warranted before re-entry.

When the Checklist Finds Something

If your walkthrough turns up evidence of current activity — droppings, gnaw marks, grease smear marks — schedule a professional inspection rather than proceeding directly to self-exclusion. Active activity means there are rodents currently inside the structure; sealing entry points before treatment traps them inside and creates a dead-rodent odor problem. The sequence is always: treat first, then exclude.

If your walkthrough finds gaps but no activity evidence, exclusion work can proceed immediately. For small numbers of gaps at accessible above-grade locations, DIY exclusion with copper mesh and polyurethane caulk is appropriate. For larger gap inventories, pier-and-beam crawl-space work, or attic-related gaps, professional exclusion is the more reliable approach.

Related Resources

• Mouse Proofing and Entry-Point Sealing
• Rodent Exclusion Services
• Free Rodent Inspection
• Mice Control Services
• Rodent-Proofing Materials That Actually Work