Roof rats (Rattus rattus) are the dominant rodent species infesting Houston attics, and their behavior makes them uniquely difficult to control. Unlike Norway rats that stay at ground level, roof rats are agile climbers that use Houston's extensive tree canopy as elevated highways to access rooflines, soffits, and attic vents.
How Roof Rats Enter Houston Attics
Houston's older neighborhoods with mature live oaks and pecans create direct pathways from branches to rooflines. A roof rat can jump up to 8 feet horizontally from a branch to a roof surface. Once on the roof, they exploit: gaps where soffit meets fascia, uncapped attic vents, ridge vent gaps, plumbing vent pipe openings, and gaps around roofline flashing.
Signs of an Active Rat Infestation
Droppings near roofline entry points and in attic pathways are the most common sign. Roof rats produce dark, pointed droppings about ½ inch long. You may also hear scratching and scurrying in the attic at night — roof rats are nocturnal and most active after dark. Grease and rub marks along rafters and insulation burrowing are clear indicators of established travel routes.
Why Trapping Alone Does Not Work
Temporary trapping eliminates the rats currently inside but does nothing about the entry points they use. Within weeks, new rats from the same foraging population find the same open entry points and re-infest the attic. Full exclusion — sealing every opening with hardware cloth, steel wool, caulk, or expanding foam — is essential.