How do I know I have roof rats?
Roof rats enter high, so attic activity is the giveaway. Listen for scratching and scurrying in the ceiling at night, and look for droppings in the attic and garage, gnaw marks on wires and wood, and grease trails along beams. A classic San Diego tell is citrus left hollowed out on the tree.
- Droppings in the attic, garage, or pantry
- Night-time scratching in ceilings and walls
- Gnaw marks on wires, wood, and food packaging
- Hollowed-out oranges or lemons still on the tree
Why are roof rats so common in San Diego?
Our climate and landscaping suit them perfectly. Roof rats are agile climbers that nest in palm fronds, ivy, and fruit trees rather than burrowing, and San Diego's mature citrus, avocado, and dense ground cover give them food and shelter year-round. From the canopy they move onto roofs and into attics, which is why they are far more common here than the ground-dwelling Norway rat.
What is the roof rat removal process?
We inspect to confirm the species and find every entry point, set traps to remove the current population, then perform exclusion by sealing roofline gaps, vents, and utility penetrations with rodent-proof materials. We finish with sanitation guidance to remove scent trails, and follow-up visits confirm the activity has stopped.
Why is exclusion the part that actually works?
Trapping removes the rats you have, but in San Diego's dense neighborhoods a new rat moves in within weeks if the holes stay open. Roof rats can squeeze through a gap the size of a quarter. Sealing every roofline gap, vent, and pipe penetration is what turns removal into a permanent fix rather than a recurring chore.
How long does it take, and what does it cost?
Most homes see activity stop within one to two weeks of trapping and sealing, with follow-up to confirm. Cost depends on the size of the home, the number of entry points to seal, and the severity of the infestation, plus any cleanup. We provide a free written estimate so you know the scope and price up front.
How do I keep roof rats from coming back?
Keep the structure sealed, trim tree and shrub branches back several feet from the roof, control ivy and dense ground cover, pick up fallen fruit, harvest citrus promptly, and secure food and pet food. Exclusion is the durable fix, and recurring service adds monitoring so a new entry point is caught early.
Common questions
In a San Diego attic it is almost always a roof rat. Roof rats are slender, agile climbers with large ears and a tail longer than their body, and they nest above ground in attics, trees, and ivy. Norway rats are stockier ground burrowers found near sewers and waterways, and they rarely climb into attics.
From the top down. They climb trees, fences, and utility lines onto the roof, then enter through gaps at the eaves and roof junctions, attic and dryer vents, and openings around pipes and conduit. A roof rat fits through a hole the size of a quarter, so finding and sealing every gap matters more than trap placement alone.
We avoid loose poison as the primary method. It risks a rat dying and decomposing inside a wall, and it endangers pets and wildlife. Trapping plus exclusion removes the rats and keeps new ones out, which poison alone never does. When bait is warranted we use tamper-resistant stations placed out of reach.
Trapping alone is a temporary fix. Without sealing the entry points, new roof rats from the surrounding neighborhood move in within weeks, because the gaps that let the first ones in are still open. Exclusion is the step that actually ends the problem, which is why we always pair it with trapping.
Most homes see activity stop within one to two weeks of trapping and sealing, with follow-up visits to confirm. Larger homes or heavier infestations take longer. We give you a clear plan and do not consider the job done until the activity has stopped and the entry points are sealed.
Yes. They gnaw constantly, chewing wiring, which is a fire risk, plus insulation, ductwork, and stored items. They also contaminate attics and pantries with droppings and urine, which carry health risks. The damage and contamination are why prompt removal and cleanup matter, not just stopping the noise.
Be cautious. Rodent droppings and nesting material can carry health risks and should not be swept or vacuumed dry, which can release particles into the air. We address droppings and contaminated insulation as part of a complete job and advise on safe cleanup, with the scope included in your written estimate.
Keep the roofline sealed, trim branches back several feet from the roof, thin out ivy and dense ground cover, pick up fallen fruit, and store food and pet food sealed. These steps remove the harborage and food that draw roof rats. A recurring monitoring plan catches any new gap before it becomes another infestation.
Written by Ronald Dean Mann II, Associate Certified Entomologist (ACE). Last updated June 26, 2026.