How can homeowners protect stored items in garages or attics from pests?

The reason this is worth doing first, rather than worth doing eventually, is timing. Manchester's first hard frost lands roughly October 19 to 29 most years (NOAA), and from there an attached, unheated garage or an attic stays measurably warmer than outdoors, undisturbed for weeks at a stretch, straight through to March. That's not a brief exposure window — it's most of a rodent's active season, and extension guidance is unambiguous that mice and rats are drawn toward exactly this kind of shelter as outdoor temperatures fall and food thins out.

A garage full of cardboard boxes, stacked on the floor, with a bag of birdseed or pet food somewhere in the mix, is an unusually generous version of what a mouse is already looking for. None of that requires anything to have gone wrong yet — it's the baseline condition in a lot of houses.

NPIC and CDC both frame rodent control around the same three variables, and a homeowner controls all three without hiring anyone. Harborage is nesting material and clutter — cardboard, loose paper, and undisturbed piles are what NPIC specifically flags for removal. Food is anything edible left in a bag or thin container; this hub's flagship storage answer already covers why metal and glass are the only container classes that reliably exclude a gnawing rodent, while paper, cardboard, and thin plastic don't. Access is the physical gap — a rodent needs remarkably little of it, and UNH Extension's core advice is to seal exterior cracks, 'paying special attention to the foundation and where pipes and utilities enter the home.'

Do all three in the same afternoon or weekend and you've addressed the standard case completely, without a single product purchase beyond a caulk gun, some hardware cloth, and a few metal containers.

Rodents travel along walls and edges far more than they cross open floor space, which is why boxes stacked directly on a garage floor against a wall get found chewed more often than the same boxes on a shelf a few feet up. A simple wire shelving unit accomplishes two things at once: it puts distance between stored goods and the floor-level travel route, and it makes it easier to actually see what's underneath and behind things during a periodic check — which matters, because nobody has visibility into what's happening at floor level behind a wall of boxes otherwise.