Norway Rat (Rattus norvegicus)

How to Identify Them

Norway rats are bulky with a blunt snout, small close-set ears and a thick tail that's shorter than the body. Droppings are large, about 3/4 inch, with blunt ends. Burrow openings are often 2 to 4 inches wide with smooth, packed edges and fresh dirt nearby.

Common look-alikes:

• Roof rat: slender, with large ears and a long tail. See our roof rat guide.
• Juvenile rats vs. mice: young rats have big heads and feet compared with their bodies; mice are proportioned smaller overall.

Signs of an Infestation

• Burrows along foundations, under slabs, sheds, AC pads or near seawalls
• Large blunt droppings in garages, sheds and storage rooms
• Gnawed doors, plastic bins and pipes at ground level
• Runways in grass or along walls
• Ground-level noises in walls or under floors

Prevention Tips

• Keep garbage in sealed cans and clean up around dumpsters.
• Remove clutter, wood piles and debris from the ground.
• Seal gaps at the base of walls, doors and pipe penetrations.
• Fill in old burrows after treatment and watch for new ones.
• Repair broken drain covers and damaged plumbing.

Norway Rats Near Canals and Seawalls

Waterfront homes are a common setting for Norway rats in South Florida. Canal banks, riprap, the gaps behind seawall caps and the soil under docks give them places to burrow close to water. From there, they forage in yards at night, raiding pet food left on lanais, fallen fruit, compost and garbage. If you live on the water, pay attention to new holes near the seawall, packed runways through the grass and gnawing on dock boxes or storage bins. Erosion behind a seawall can also open voids that rats move into. A careful inspection of the waterline, the yard and the base of the home tells us where to place stations and traps and which openings need to be sealed.