What we close
Roof rats are the animal in these attics. They use tile roofs, palm trees, and any gap about the size of a quarter. The openings we actually find are at the fascia, the soffit returns, the plumbing stacks, the gable vents, and the holes the air-conditioner lines pass through.
The fix is a material they cannot chew apart. Hardware cloth, one-quarter inch, fastened so it cannot be pushed. Sheet metal over a larger hole. Copper mesh packed into a small gap. Spray foam by itself is not rodent proofing. They chew through it. Chicken wire is not the mesh either. They get through it.
A soffit vent stays a vent. We screen it. We do not board it shut to 'keep the rats out' and kill the attic ventilation.
What we do not do
We do not set traps. We do not put out poison. We do not claim a pest-control license. If rats are living in the attic, a licensed pest-control company gets them out first. Sealing the holes while they are still inside kills them in the walls.
Droppings and nesting in the insulation are not a proofing-only job. That fill comes out, the deck gets treated, the holes get closed, and then new insulation goes down. Those are separate prices. Proofing does not include the removal.
The order
Animals out first, if they are still in the house. Then the bad insulation, if it is contaminated. Then the holes, while the deck is visible. Then the air seal for the heat, which is a different set of gaps. Then the new blow, if you want one.
Closing holes and blowing over dirty fill leaves the droppings in the ceiling. We will not do that to get the job done in one trip.
Contaminated fill is insulation removal, then attic sanitizing. The new blow, if you want one, is after the holes are closed.