Why does trapping alone not stop roof rats from coming back?
Trapping removes the rats in the attic, but the openings and the routes stay. New rats from the same trees, fences and neighbors find the same gaps. Exclusion closes the openings, and habitat changes cut the access. Together they make a lasting result more likely, though none is guaranteed.
A roof rat colony in a neighborhood is not limited to one house. UC IPM says roof rats are present in almost all California cities, and a mature yard next door may be a source. The job is to make your house the hardest one on the block to enter.
Ask the technician to point out each gap on the roofline and mark it in the written report. That list is your record of what was sealed.
Where do roof rats get into a house?
Roof rats get in wherever an opening is larger than a nickel, according to UC IPM. Common spots are roof and soffit vents, gaps at the eaves, pipe and cable penetrations, damaged fascia, garage door seals and gaps where tree branches or wires touch the roof.
Rats use branches, fence tops and cables as bridges. A branch within a few feet of the roof is a highway, so trimming it is part of the job.
Older homes often have gaps where rooflines meet additions, or lost screens on gable vents. Newer houses can have gaps at penetrations that settled after construction. Neither type is immune.
- Roof, gable and soffit vents without metal mesh
- Gaps where pipes and cables enter the wall or eave
- Damaged fascia and soffit boards
- Worn garage door seals and gaps at the corners
- Branches, wires and fences that touch or sit near the roof
What yard changes help keep roof rats out?
Trim branches back from the roof, thin dense ivy and shrubs near the house, pick up fruit and nuts, and fix leaking faucets and sprinkler heads. UC IPM names mature landscaping, riverbank vegetation, birdbaths, fountains, plant saucers, pet bowls and air-conditioner condensate lines as habitat or water sources.
Do not clear everything before the visit. The technician uses the yard to find the runways. Make the changes after the inspection, and keep them up through the dry months.
If you have fruit trees, picking up the fruit regularly matters more than most people expect. A heavy crop on the ground is a free meal and nesting cover for rats at night.
Is it safe to be in an attic with roof rats?
Avoid handling droppings, nesting or dead rats without protection, and do not sweep or vacuum dry droppings, which can put dust into the air. Gnawed wiring is also a fire risk. Leave the attic to the technician and ask what cleanup the written report recommends.
If you hear rats, have the electrical wiring checked after the rats are removed. Gnawing on wire insulation is a known rodent behavior, and a technician can point out damage they see, though they do not do electrical repairs.
What does the written report show after exclusion work?
The written service report lists where rats were entering, which openings were sealed and with what, where traps were set and what was caught, and what remains open or needs separate repair. It also records the habitat changes recommended, such as trimming branches and fixing irrigation leaks.
Use the report as a checklist. Walk the roofline with it after the visit and again after the first heavy rain, and call if you hear activity or see a gap that is not on the list.
If a repair is outside the visit, for example rotted fascia or a missing vent cover, the report says so and the technician quotes it separately. You decide what to approve, and nothing is started before you agree on the price.
