Every fall, mice and rats in Middlesex County seek warm shelter indoors. The prevention window closes fast — here's how to seal your home.
Every fall in Middlesex County, the same thing happens: temperatures drop, food sources outside diminish, and mice and rats begin actively seeking warm harborage. Your home, with its steady warmth, indoor food sources, and abundant hiding spots, is exactly what they're looking for. The good news is that rodent exclusion — sealing entry points before they find them — is highly effective when done right.
When to Act
The exclusion window in Middlesex County is September and October. By November, mice that are going to move inside have largely done so. Early-season exclusion is proactive; late-season exclusion may be reactive to an existing infestation.
How Mice Get In
A house mouse can squeeze through a gap the size of a dime. Norway rats need a hole roughly the size of a quarter. Both species exploit openings that homeowners never think to check:
Foundation and sill plate area: Gaps where the sill plate sits on the foundation wall, cracks in the foundation, and gaps around utility penetrations (gas lines, water lines, electrical conduits) are primary entry points.
Garage doors: The gap at the bottom of an aging garage door seal is a common entry point. Side gaps and the threshold seal often fail over time.
Utility and HVAC penetrations: Every pipe, wire, and conduit that enters the building through the foundation or wall is a potential entry point if not properly sealed.
Crawl space vents: Deteriorated or unscreened crawl space vents allow direct access to the under-floor space, from which mice access wall voids throughout the structure.
Roof and soffit areas: Norway rats in particular are excellent climbers. Gaps at fascia boards, deteriorated soffit panels, and roof vents without hardware cloth backing are potential entry points for roof rats and squirrels.
Door sweeps and threshold seals: A quarter-inch gap at the bottom of an exterior door is sufficient for mouse entry. Door sweeps wear out over time and should be replaced when damaged.
Exclusion Materials
Not all exclusion materials are equal. Mice can chew through soft materials given motivation:
- Steel wool or copper mesh — for stuffing into gaps around pipes (follow with caulk over top) - Hardware cloth (1/4 inch mesh) — for covering vent openings, crawl space vents, and larger openings - Concrete or mortar — for foundation cracks - Metal kick plates and door sweeps — for door gaps - Expanding foam — acceptable for large gaps away from direct rodent access, but should not be the primary exclusion material in high-risk areas (mice can chew through it)
Professional Exclusion Service
A thorough professional exclusion inspection will identify entry points that are easy to miss — including gaps hidden behind landscaping, under decks, and at the roofline. Professional exclusion work uses appropriate materials for each opening type and provides a foundation for long-term rodent prevention.
Exclusion alone may not be sufficient if an active infestation already exists. In that case, elimination of the existing population must occur simultaneously with exclusion work to prevent trapping animals inside.
Contact Middlesex County Pest Control for a fall rodent exclusion inspection throughout Middlesex County.
Frequently Asked Questions
When should I do rodent exclusion work in NJ?
September and October are the ideal months for rodent exclusion in Middlesex County — before mice and rats actively begin seeking winter harborage. Early fall proactive exclusion is far more effective than waiting until you see signs of entry.
What is the most common entry point for mice?
Gaps around utility penetrations (pipes and wires entering the foundation), deteriorated sill plate areas, garage door seal gaps, and crawl space vents are the most common entry routes for mice in NJ homes.
Can mice chew through foam sealant?
Yes. Expanding foam alone is not a reliable rodent exclusion material. Use steel wool, copper mesh, or hardware cloth as the primary barrier, and apply caulk or foam over the top for weather sealing.
How do I know if mice are already inside my home?
Look for droppings (especially in kitchen cabinets, under sinks, and in crawl spaces), gnaw marks on food packaging and wood, nesting material in tucked-away areas, and grease marks along baseboards.