There’s a week every fall, usually right after the first night in the 30s, when half the calls into our Lawrence Township office are about mice. Droppings in the garage in Hamilton Square. A chewed bag of birdseed in a Ewing basement. Scratching in a kitchen ceiling off Route 1 in Lawrenceville. It happens on the same week every year because mice do what everyone else in Central Jersey does when it gets cold: they go inside.
Why it’s always October
House mice live outdoors all summer, in the mulch beds, under the deck, in the woodpile and along the foundation. They don’t need your house until the ground cools and the seeds and insects thin out. Then they follow warmth. A mouse can get through a gap the width of a pencil, and it finds the warm air leaking out of a garage door seal, a dryer vent, a gap around the AC line set or the spot where a deck ledger meets the siding. Once one is in, its scent trail brings the rest.
The neighborhoods around our office are built for this. Hamilton, Ewing and Lawrence are largely post-war ranches, capes and split-levels, thousands of similar houses reaching the same age at the same time. Original garage door seals have flattened. Soffit vents have lost their screens. Additions from the 1970s and 80s meet the old foundation at a seam that has opened a little more every winter. And because the lots are close together, a mouse problem on one street becomes the neighbors’ problem by Thanksgiving.
What you’re seeing, and what it means
Droppings are the giveaway: dark, rice-sized, concentrated along walls, behind appliances, in the back of cabinets and on garage shelves. A mouse produces dozens a night, so a small pile means a few days, not a few hours. Gnaw marks on food packaging, pet food bags and the corners of cardboard boxes come next. A faint ammonia smell in a closet or utility room means the activity has been going on a while. And the scratching in the walls or ceiling at night that stops when you turn the light on is the sound of a nest, not a visitor.
Rats are a different animal and a different job. Around here they’re most common near the commercial corridors along Route 130 and Route 33, near the river in Trenton, and anywhere with a sewer connection issue. Rats burrow around foundations rather than nesting in walls. If the droppings are larger and you’re seeing burrows or greasy rub marks along the outside of the house, that’s the call to make sooner rather than later.
Why the trap-and-forget approach doesn’t hold
A few snap traps in the garage will catch mice. They will not stop mice. As long as the gap they came through is open, new mice replace the ones you trapped, and by January you’re on your third box of traps and the smell is worse. The homeowners who call us every fall are almost always the ones who trapped their way through the previous winter and never had the entry points closed.
Our rodent control visit does two jobs at once. Inside, traps and bait stations go where the activity actually is, along the walls and behind the appliances, not scattered across the floor. Outside, we walk the foundation, garage, utility penetrations and roofline with a flashlight and a tube of sealant, and we close what we find with materials that hold up to chewing and weather. Where the property warrants it, exterior bait stations intercept activity before it reaches the house.
The case for a plan
Rodent pressure in Mercer County is seasonal and it comes back every year, which is exactly the argument for putting the house on a plan instead of making an emergency call each October. Our Comprehensive Rodent & Pest Defense Plan, from $65 a month, includes mice with interior stations placed as needed, exterior stations as an add-on, four seasonal visits and unlimited callbacks between them. It’s cheaper than one bad winter, and it means someone is checking the entry points before the mice do.
It also matters for the house. Mice chew wiring and insulation, which is a fire risk, and they contaminate food and surfaces. A colony that’s been in an attic all winter has soiled the insulation by spring, and that’s a much more expensive fix than a fall visit.
What you can do this week
Replace the garage door bottom seal if daylight shows under it. Put birdseed, pet food and grass seed in sealed bins. Pull mulch and firewood back from the foundation. Check where the dryer vent, AC line and cable enter the house and stuff any gap with steel wool as a stopgap. None of that replaces a proper sealing job, but it slows things down until we get there.
If you’re in Hamilton, Ewing, Lawrence, Trenton or anywhere else in Mercer County and you’ve already heard the scratching, call 609-356-PEST (7378) or request a free inspection. We’re twenty minutes from anywhere in the county.