Home › Rodent Exclusion
Exclusion is the part of rodent control that ends the problem instead of renting a solution to it. It means finding every opening a mouse or rat can use, down to a gap the size of a dime for a mouse, and closing it with materials the animal cannot chew, push or pull out.
Buffalo is hard on houses. Freeze and thaw cycles work on fieldstone and mortar every winter. Balloon-frame walls give anything that reaches the sill a clear run to the attic. Add a century of pipe, wire and cable additions, each one drilled through the foundation or rim joist, and most older homes here have a dozen entry points the owner has never seen. This page is about how we find them and close them.

A mouse needs its skull to fit. The rest of the body compresses. That is why openings that look too small to matter are exactly the ones that do. Rats need roughly a half inch, and they will gnaw a smaller hole bigger if the material lets them.
Materials matter more than effort. Foam alone is a snack. We use galvanized steel mesh and hardware cloth over larger openings, copper mesh packed into irregular gaps because it does not rust and rodents dislike chewing it, sheet metal flashing where a flat barrier is needed, and professional sealants as the finish layer, not the only layer.
On masonry, that means repointing and packing failed mortar joints in fieldstone, and sealing the sill gap from outside where it is reachable. On frame houses it often means work at the siding line and the rim joist. Every sealed point gets checked against the map from the inspection, so nothing on the list is left open.
Sealing a house with animals still inside trades one problem for another. The order of work is inspection, removal of the animals that are in, then sealing, then a check that activity has stopped. Our mouse and rat programs are built that way, and the process page lays out the full sequence.
Done in the right order, exclusion is the closest thing rodent control has to a permanent result. The house stops advertising itself. The fall migration that fills Buffalo attics in October runs into a closed structure and moves on to easier targets.
Honest limits. Exclusion seals your structure. It does not remove a rat colony living under a neighbor's shed, fix a broken city sewer, or stop mice from living in your yard and garage if the garage is left open and full of bird seed. For yard-level problems, exclusion pairs with the trapping and habitat work on the rat page and the mole and vole page. We will tell you at the inspection which parts of your problem sealing will solve and which parts it will not.
Exclusion pays back fastest on the houses Buffalo has the most of. Pre-war doubles with balloon framing, where one sill gap serves every floor. Homes with fieldstone or rubble foundations, where the entries are in the mortar and change a little every winter. Houses that have been added onto, because every addition seam is a route. And homes that have already paid for trapping once and watched the problem return the next fall: that history is the clearest sign that the building, not the animals, is the problem left to fix.
It is also the service landlords get the most from. A sealed double stops generating the same tenant call every October, and the work is documented for the property file. The residential page covers how exclusion fits into a whole-building plan for rentals.
Steel mesh, hardware cloth and flashing do not wear out on a schedule. What ends exclusion work is the house moving: freeze and thaw shifting a fieldstone joint, a new utility line drilled through a sealed rim joist, a door sweep tearing, a vent cover cracked by a ladder or a storm. That is why the honest version of this service includes a look, once a year in the fall, at the points that were sealed and the points that did not exist yet. Five minutes with a flashlight in September is most of it, and the winter proofing guide gives the homeowner version of that checklist.
Your part is small but real: tell us about any new holes drilled, lines run or vents replaced since the sealing, and do not re-open a sealed vent for a dryer or a fan without a rodent-proof cover going back on it.
Exclusion is priced by the opening: how many there are, how big, and what each one takes. A dozen small pipe and wire gaps is a mesh and sealant job. A failed stretch of fieldstone mortar is repointing. A roofline opening that needs a ladder and flashing is sheet metal work. Access matters too; a sill gap you can stand next to in the basement costs less of the day than the same gap behind a finished wall.
The cost page puts Buffalo market ranges on exclusion next to the other services, so you can see where this work sits before the inspection gives you your number. The inspection list itself is the quote: every opening on it, priced, so you can approve the whole list or stage it.
Removal comes before sealing. The mouse program clears the house so exclusion can close it.
The inspection builds the opening-by-opening list that exclusion work is priced and done from.
Once the house is sealed, cleanup resets the attic so old scent stops advertising the route.
Stops a mouse. The mesh grade and the gap standard this whole service is built around.
Roughly what a rat needs, and a rat will gnaw a smaller soft opening bigger. Hard materials are the point.
Do most of the work: copper mesh, steel mesh and hardware cloth, sheet flashing, and mortar in masonry.
Five minutes with a flashlight on the sealed points. Houses move; the check is what catches it.
Materials are the cheap part of exclusion. Matching the right one to the opening is the skilled part. This is the working list.
| Material | Used at | Why it holds |
|---|---|---|
| Copper mesh | Irregular gaps around pipes, wires and cables | Does not rust, packs into odd shapes, and rodents dislike chewing it |
| Galvanized steel mesh & hardware cloth | Vents, foundation holes, soffit and crawl openings | Teeth lose to it. The quarter-inch grade is the mouse-proof standard |
| Sheet metal flashing | Siding lines, roof junctions, flat gnaw edges | A hard face where a barrier has to be flat and weatherproof |
| Mortar and repointing | Failed joints in fieldstone and rubble foundations | It is the foundation's own material, repaired the way a mason would |
| Sealant and foam | Over and behind the metal, as the finish layer | Air sealing and weather only. On its own, foam is a snack |
Some of it, yes. Door sweeps, vent covers and obvious pipe gaps are fair game for a handy homeowner, and our winter proofing guide lists them. The misses are usually the hidden ones, at the sill behind the siding, inside the rim joist, or at the roofline. If mice keep getting in after your own sealing pass, the remaining gap is one of those.
Yes. Rats use bigger openings, so the work is heavier material and more of it at ground level, including burrow mouths at the foundation. The principle is the same. Close the structure and the animals have to live somewhere else.
Not the way we sequence it. Removal comes first and the inspection confirms where activity is active. One-way exits can be fitted on a main entry when there is any doubt, so anything left inside can get out and cannot get back in.
Steel, copper and hardware cloth do not wear out on any schedule you need to worry about. Mortar and sealant on an old foundation deserve a look every few years, because the house keeps moving with the seasons. We point out the spots worth watching when the job is done.
For Buffalo landlords it is usually the best money in the whole problem. A sealed double stops the repeat calls every October, and it protects the building itself. See the landlord notes on the residential page.
Both, because Buffalo mice use both. In balloon-frame houses the attic is reached from inside the wall, but soffit gaps, porch roof junctions and vent openings are separate entries and they are on the inspection list. Sealing the foundation and leaving the roofline open is half a job.
It happens, usually at a spot the house changed: a shifted joint, a new cable run, a torn door seal. A fall check catches most of them before the mice do. Call when you find one and a single opening is a small visit compared with a full re-sealing.
Almost certainly the rest of the list. A Buffalo house with one open gap usually has several, and sealing the two you can see from the basement floor leaves the rim joist, the roofline and the utility holes open. The mice are not outsmarting the seal; they are using a different door. This is the exact frustration an inspection exists to end: the whole shell read at once, every opening graded and priced, so the sealing is done as one complete job instead of a room-by-room chase.
Call now and tell us what you are seeing. We will walk you through the next step and get an inspection set up.
Sounds in the walls, droppings in the wrong place, a smell that will not air out. The inspection names the animal and the entry points before you spend anything on treatment.
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