Los Angeles is one of the worst roof rat cities in the country, and if you have rats in an LA home, roof rats are almost always what you are dealing with. They thrive in the mild climate, travel the palms, fruit trees, ivy, and power lines, and drop into attics from the roofline. Norway rats stay lower, near alleys, drains, the LA River, and crawlspaces. Both leave the same signs: droppings, gnaw marks, grease trails, and scratching in the walls at night. We handle rats the way that actually works in this city, by finding every way in, sealing it, and removing the rats already living on the property.
Why roof rats thrive in Los Angeles
LA is built for roof rats. The warm, dry climate lets them breed nearly year-round, and the landscape gives them everything they need. Palm trees, citrus and avocado trees, thick ivy, and dense ornamental hedges all feed and shelter roof rats, and the hills and canyons from the Hollywood Hills to the Verdugos and the Santa Monica Mountains act as reservoirs that push rodents into the neighborhoods along their edges.
Roof rats are climbers. They run fences, utility lines, and tree branches that touch the house, then use the roof as their doorway. Once they reach the roofline they look for the gaps most homeowners never check: where the roof meets the eaves, around vents and the chimney, and where different rooflines join. Older LA housing, from Craftsman bungalows to Spanish homes and mid-century apartments, tends to have plenty of those gaps.
Signs you have rats, not mice
Rat droppings are large, up to three quarters of an inch, and you tend to find them concentrated along runways in the attic, garage, or behind stored boxes. Rats also leave darker grease marks where they squeeze through the same gap over and over, and their gnaw damage is coarser, on wood, wiring, irrigation lines, and even soft metal.
Sound is the other giveaway. Roof rats are active after dark, so scratching, gnawing, and scurrying overhead in the ceiling or attic in the evening usually points to rats rather than mice. If you are seeing chewed fruit under the trees or hollowed avocados, that is a roof rat signature.
How we handle a rat problem
The job starts with a full inspection, inside and out. We get into the attic and crawlspace, walk the roofline, and check the yard so we know where the rats are getting in and where they are nesting. Rats can enter through a gap the size of a quarter, so the small openings matter as much as the obvious ones.
Next we seal. Entry points get closed with steel mesh, hardware cloth, and sealant that rats cannot chew through, from vent gaps and roof junctions to the openings around pipes and the garage. Sealing is what separates a lasting fix from a treatment that fails in a month, because trapping alone just makes room for the next rat to move in.
Then we remove the rats already inside with snap traps and tamper-resistant bait stations placed along their runways. We come back to check and reset, and a follow-up visit confirms the activity has stopped before we call the job done.
Damage rats cause when they are left alone
Rats do not just live in the attic quietly. They gnaw wiring, which is a real fire risk, chew through irrigation and plumbing lines, and shred and soil insulation as they nest. Their droppings and urine contaminate the spaces they occupy, and a roof rat population can grow quickly in LA's long warm season. The sooner the entry points are sealed and the colony is cleared, the less damage and cleanup you are left with.