How to Get Rid of Norway Rats

How to Get Rid of Norway Rats

Good sanitation and sealing the building come first, and trapping is usually the safest way to deal with rats that are already inside. Norway rats climb less than roof rats and travel along the floor, so put traps low and out of sight: tight against walls, behind appliances and stored boxes, in dark corners, and anywhere you have found droppings or gnaw marks. Set each snap trap at a right angle to the wall with the trigger end almost touching it, so a rat running along the wall crosses it directly. Keep every trap where children and pets cannot reach it, or place traps inside a covered trap box.

Sealing, cleanup and trapping tips for ground-dwelling rats

Trapping removes the rats you have. Keeping others from replacing them takes changes around the building:

• Seal low openings. A rat can get through a gap about half an inch wide. Close gaps around pipes, AC lines, garage doors and foundation vents using metal flashing, hardware cloth, concrete or mortar, since rats chew through plastic, foam and wood.
• Block burrowing. Around sheds, decks and slab edges, bury hardware cloth along the base and bend it outward in an L shape so rats digging down hit the barrier.
• Remove food and cover. Bring pet food in at night, store feed and seed in metal bins, pick up fallen fruit, keep garbage lidded, and clear woodpiles, debris and dense ground cover from the foundation.
• Fix water sources. Repair leaky faucets, irrigation lines and AC drain lines.

When trapping, leave traps baited but unset for a few days. Norway rats are wary of new objects, and letting them get used to the traps first makes catches more likely. Use plenty of traps rather than one or two.

Mistakes to avoid include filling burrows without removing the rats, since they simply dig new ones; moving traps every day; and using poison bait inside the home, where a rat may die in a wall and leave an odor that attracts bottle flies.

A professional service involves an inspection for burrows, runways and entry points, trapping or baiting in secured stations where appropriate, exclusion work to seal the structure, and follow-up visits to monitor activity.