Which squirrel are you actually dealing with?
Start with where the evidence is, because the answer changes the entire plan. Sound overhead, chew marks at a roof edge, and a worn track along a fascia board mean a tree squirrel. Open holes with fresh soil beside them, worn runways along a fence line, and settling near a slab edge mean a ground squirrel. The distinction is not academic. Attic animals are handled with one way doors and metal over openings, and the timing revolves around litters. Burrowers are handled in the yard on a soil moisture schedule that UC IPM splits into fumigation months from February through June and baiting months from June through October. Species also decides the legal picture. Across the West, introduced eastern grays and fox squirrels are generally unclassified, while native western squirrels are often protected, and in Washington the western gray squirrel carries threatened status. Arizona has its own rules, so the safe move is to ask Arizona Game and Fish rather than assume. A company that names the species out loud and explains how it knows is worth more than one that quotes a price before looking.
A month by month picture for Tucson homes
There is no dormant stretch here, so think in terms of breeding and food rather than cold. Late winter is the first pressure point. Penn State Extension puts gray squirrel breeding around mid December or early January, which means February and March bring nursery noise into attics: a heavier, rolling sound rather than the quick scurry of a single animal. Spring is when ground squirrel work is most effective, since the soil still holds moisture and adults are above ground from mid January onward. It is also the best stretch for repairs, before the roof becomes unworkable. June brings the second breeding period and, with it, the same warning about sealing anything shut. From July through September, Tucson's 100F afternoons compress activity into the first and last hour of daylight, and homeowners often assume the animal left because the middle of the day is silent. Fall is caching season. Chewing on trim, stored items, and irrigation tubing steps up as animals gather and hide food, and that is when a small opening becomes a large one.
What the first visit should actually cover
The first appointment is a survey, and you should judge a company on it. Someone walks the whole exterior looking at the fascia line, the soffit returns, the gable louvers, the attic fan housing, the tile roof edge where a bird stop has broken out, and the seam where a patio cover ties into the wall. Then they get into the attic if it can be entered safely. Up there the tells are droppings, matted nesting, chewed sheathing, stripped wire, and daylight. Daylight is the whole exercise. Every pinhole of light is an opening that has to be closed before anyone calls the job finished. What you should hold at the end is a written map: how many openings, where each one is, and what material goes over it. Half inch hardware cloth or metal flashing screwed to sound wood is the answer. Foam, caulk, and plastic screening are not. Ask two more questions before signing. When do the doors come off, and does the price include the carpentry or only the animal work.
What sets the price on a Tucson squirrel job
Nothing about this work has a list price, and the honest companies say so before they visit. Five variables do the work. Opening count comes first. One chewed corner over a carport is an afternoon. Six gaps along a long soffit run, plus a torn gable screen and a lifted tile edge, is a full day of ladder work with metal and fasteners. Litters come second. Hit the job in a birth window and the crew has to leave the door off and come back, and every return trip lands on the invoice. Insulation is third. Blown in insulation that has been fouled comes out and gets replaced. In an attic that bakes under Tucson sun, nobody is cleaning it in place. Roof access is fourth. Tile, steep pitch, and high gable ends all need staging. Follow up is fifth, and it is the line people forget to ask about. Get all five written separately, because two bids only compare honestly when you can see what each one left out.
Renters, landlords, and who pays
A hole chewed through fascia is a defect in the building, so in most rental situations the repair belongs to the owner rather than the tenant. Tenants do not own the roof edge, and a structure that animals can walk into goes to habitability. If you rent, put it in writing the day the noise starts. Note the room it is over, the time of day, and how long it runs. Photograph anything visible from the ground. Dated records settle disagreements that spoken reports never do. Tenants can still weaken their own position. Bird feeders on a patio, pet food left out overnight, a dripping hose bib nobody reported, and months of silence about the scratching all shift the argument. Owners of Tucson rentals do better by moving early. Screening vents, wrapping soft trim in metal, and keeping limbs off the roof costs a fraction of an attic full of soiled insulation. Ask the contractor for an invoice that names each opening found and the repair made to it, since either side may need that paper later.