What is the best time to inspect for pests in homes before winter?

This isn't a generic "do it sometime in fall" recommendation -- there's a specific mechanism behind the date. Rodents seek winter shelter inside buildings following the first cold spell each fall, which means the trigger for indoor migration is a weather event, not a calendar date on its own. Manchester's frost risk begins around October 4 and becomes nearly certain by October 29, so an inspection done in late September through mid-October happens before that trigger, while gaps are still easy to find and no rodent yet has a behavioral reason to be searching for one.

An inspection done after the first hard frost has already passed is inspecting after the trigger has fired -- which can still find and close gaps, but it's addressing a home that may already have new occupants rather than preventing them from arriving in the first place.

The specific target is entry gaps at the sizes CDC identifies as functional thresholds: roughly 1/4 inch for mice, about the width of a pencil, and 1/2 inch for rats, about the size of a nickel to a half-dollar. That means the inspection isn't a vague walk-around -- it's a focused check of foundation cracks, utility penetrations, door sweeps, vents, and any gap near where pipes or wiring enter the structure.

Most of what an inspection at this stage finds is a homeowner job: steel wool packed into a small gap, caulk at a sill plate, a new door sweep. A smaller number of findings, larger structural openings, gaps high on a roofline, are a trade or professional job. The inspection's value is telling you honestly which category each gap falls into.

The honest answer here is not to treat this as ruined. Inspecting and sealing still works in the middle of winter -- it's simply a different job at that point, since the goal shifts from pure prevention to finding and closing gaps that may already have rodents on the other side of them. Snow cover makes foundation-level gaps harder to spot, which is the practical reason earlier is better, but it doesn't make a mid-winter inspection worthless.

What changes is the follow-up: a mid-winter inspection should pair with the sign-based checks described elsewhere in this cluster, droppings, gnaw marks, nighttime scratching, since you're now checking for both open gaps and evidence that something has already used one.