How to Get Rid of Rats (DIY Guide)

The two rat species you'll encounter in the US are:

• Norway rats (brown rats) — The most common. Stocky, 7–10 inches long (body), with a shorter-than-body tail. They're ground-dwellers that burrow under foundations, along fences, and under debris piles. They enter homes at ground level.
• Roof rats (black rats) — Slimmer, 6–8 inches long (body), with a longer-than-body tail. They're excellent climbers and typically enter homes through gaps in the roof, attic vents, and along tree branches that touch the house. Common in southern states and coastal areas.

How to tell rats from mice: Rat droppings are ½–¾ inch long (the size of a raisin). Mouse droppings are ⅛–¼ inch (the size of a grain of rice). Rats leave larger gnaw marks and their tracks and rub marks are wider. If you're unsure, the droppings are your best clue.

Here's why rats are harder than mice: rats are neophobic — they're suspicious of new objects in their environment. A mouse will explore a new trap within hours. A rat may avoid it for days or weeks. This makes trapping significantly more challenging.

• Snap traps designed for rats — Regular mouse traps are too small. Get rat-sized snap traps. You'll want at least 6–12.
• Bait — Peanut butter, bacon, dried fruit, or nuts. Wire or tie bait to the trigger so rats can't steal it.
• Steel wool and hardware cloth (¼ inch) — For sealing entry points. Rats need a bigger hole than mice (about ½ inch or the size of a quarter), but they can gnaw through most materials except metal.
• Caulk and expanding foam — For sealing, combined with steel wool or hardware cloth.
• Heavy-duty gloves — Rat droppings and urine can carry serious diseases including leptospirosis and hantavirus.
• Disinfectant — For cleaning contaminated areas.

Step 1: Confirm Rat vs Mouse

Check droppings (raisin-sized = rat, rice-sized = mouse), gnaw marks (¼ inch+ tooth marks = rat), and grease marks (wider, darker rub marks along walls = rat). This matters because the trapping and exclusion approach differs.

Step 2: Find Activity Areas

Look for droppings, gnaw marks, grease trails along walls and pipes, burrow openings near foundations (Norway rats), and gnaw marks near the roofline (roof rats). Follow the evidence to understand their routes through your home.

Step 3: Pre-Bait Before Trapping

Because rats are suspicious of new objects, spend 3–5 days placing unset, baited traps along their runways. Let them get used to feeding from the traps. This dramatically increases your catch rate when you finally set the triggers.

Place traps perpendicular to walls with the trigger end touching the baseboard, just like with mice but using rat-sized traps. Space them every 15–20 feet along known rat pathways.

Step 4: Set and Monitor Traps

After the pre-baiting period, set all traps simultaneously. Check daily. Dispose of caught rats in sealed bags using gloves. Reset with fresh bait.

Trap tip: Wire or tie the bait to the trigger using thin wire, dental floss, or thread. Rats are dexterous enough to lick peanut butter off a trigger without setting it off. Securing the bait forces them to tug on the trigger.

Step 5: Seal Entry Points

Rats need a larger gap than mice — about ½ inch (the size of a quarter). But they're also stronger chewers. Use ¼-inch hardware cloth (galvanized metal mesh) to cover larger openings. Stuff steel wool into smaller gaps, then seal with caulk or cement. For Norway rats, check foundation-level gaps. For roof rats, check roofline gaps, attic vents, and where pipes exit the roof.

Step 6: Eliminate Food and Harborage

• Secure all food in metal or glass containers (rats chew through plastic).
• Remove fallen fruit from yards.
• Secure garbage and compost bins with rat-proof lids.
• Clear dense ground cover and debris near the foundation.
• For roof rats: trim tree branches at least 4 feet from the roofline.

• Exclusion is everything — Seal every gap ½ inch or larger with metal materials (hardware cloth, steel wool + caulk, metal flashing). Rats can chew through wood, plastic, and even aluminum.
• Tree management — Roof rats use overhanging branches as highways to your roof. Maintain a 4-foot clearance between tree limbs and your roofline.
• Eliminate food sources — Pick up fallen fruit, secure pet food, keep garbage sealed, and remove bird feeders if rats are a problem (or switch to seed types rats don't prefer, like nyjer/thistle).
• Remove harborage — Woodpiles, junk piles, dense ivy, and thick ground cover near the house provide rat shelter. Keep a clear zone around your foundation.

• Using mouse traps for rats — Mouse traps aren't strong enough to kill rats humanely and may just injure them, making them trap-shy. Always use rat-sized traps.
• Skipping the pre-bait phase — Unlike mice, rats won't approach new objects immediately. Pre-baiting for 3–5 days is critical for success. Impatient trapping catches far fewer rats.
• Using poison indoors — Rat poison (rodenticide) creates the same problem as with mice — rats die inside walls, creating a horrible smell. It also poses secondary poisoning risks to pets and children. Trapping is safer for indoor use.
• Not sealing entry points — Trapping without exclusion is an endless cycle. New rats will enter through the same gaps.
• Underestimating the problem — A single rat sighting usually means more. Norway rats live in colonies, and roof rats are social. Assume you have at least 3–5 rats for every one you see.