Rats in your attic can spread disease, cause fires by chewing wires, and damage your home's structure. The best way to get rats out is to first block off all entry points, then trap and remove any rats still inside, and finally clean up and keep them from returning. Poison is not recommended because it can create bigger problems like dead animal smells and secondary pests. Here's exactly how to do it, even with no prior experience.

Note: In New Hampshire, Norway rats (the most common species) rarely nest in attics — they prefer ground-level and basement locations. If you're hearing sounds in your attic, the pest is more likely house mice or Eastern gray squirrels. Rats in NH attics do occur but are less common than in warmer-climate states.

Find Out How Rats Are Getting In

Rats can squeeze through holes as small as a quarter or even smaller. Common spots are roof edges, vents, pipes, and gaps in eaves or siding. To find every spot:

• Check your attic in daylight. Look for where sunlight shines in or feel for drafts.
• Look outside your house for cracks, chewed holes, or gaps at rooflines, soffits (the area under roof edges), vents, chimneys, loose siding, or around pipes and cables.
• Look for smudge marks (rub marks) or droppings along beams or in insulation, which can show you where rats travel.

Seal Up Every Entry Point

You must close every hole, or the rats will keep coming back. Use sturdy materials because rats chew through wood, some plastics, and caulk. Recommended options:

• Use steel mesh (like hardware cloth with 1/4 inch holes) over vents and bigger gaps. Secure it with screws, not just staples.
• Fill small holes and cracks with steel wool first, then cover with caulk, foam, or mortar.
• Repair shingles, fascia boards (the band along the roof edge), and any broken vents or screens.
• Double-check: leave ONE main suspected hole open temporarily for trapping, seal all others right away.

Attic exclusion is specialized work. Entry points at the roofline (soffits, fascia gaps, gable vents, ridge caps) require ladder work and roof access. If you are not comfortable working at height, this is a job for a professional. Anchor Pest offers attic exclusion services across NH — call (603) 785-0118 for an assessment.

Trap and Remove Rats Already Inside

Once you've sealed most holes, rats trapped inside will be desperate to find food and exits. Traps are the most effective and humane option. Here's what to do:

• Use snap traps (recommended), which kill rats instantly. Place them along attic beams, walls, or near droppings and gnaw marks — rats travel along edges, not in open space.
• Bait traps with peanut butter, bacon, dried fruit, or Nutella. Use small amounts so rats must trigger the trap to get the food.
• Check traps daily. Remove dead rats wearing gloves and seal them in a plastic bag before disposal. Wash your hands well afterward.
• If you have many rats or a strong smell, start with at least 6–12 traps for a typical attic.
• Never use glue traps — they're inhumane and can catch non-target animals.
• Never use poisons (rodenticides) in an attic. Rats can crawl away and die in walls, causing unbearable odor and attracting more pests (insects, flies, even bigger animals).

Clean Up and Make Your Attic Unattractive to Rats

Rats leave urine, droppings, and nesting materials that smell and can make people sick.

• Wear gloves and a mask (best is an N95 mask). Clean up all droppings, nests, and contaminated insulation.
• Spray droppings and urine with disinfectant or a mix of 1 part bleach to 10 parts water; let it soak before wiping or vacuuming with a HEPA filter vacuum.
• Replace heavily soiled insulation and check for chewed wires or damage to woodwork.
• Store anything you keep in the attic in sealed plastic containers, not cardboard boxes (rats chew cardboard for nests).

If rats have been in your attic for more than a few weeks, the insulation is almost certainly saturated with urine and droppings. Contaminated attic insulation must be removed and replaced — it cannot be safely cleaned in place. This is a significant remediation cost ($1,500–5,000+ depending on attic size) that homeowners should budget for alongside the pest removal treatment.

Prevent Rats From Coming Back

Now that your attic is rat-free, stop new rats from moving in:

• Finish sealing that last hole you left open after confirming all rats are gone. Block it as described above.
• Trim tree branches a few feet from your roof; rats climb trees and jump onto roofs.
• Keep wood piles, dense shrubs, and debris away from your house's foundation.
• Fix any leaks or water in gutters — rats need water and are attracted to damp areas.
• Don't leave pet food or birdseed outside overnight. Empty garbage regularly and use secure cans.

When to Call a Professional

If the problem is overwhelming, if you can't safely access your attic, or if you can't find all the entry points, call a licensed pest control specialist. Professionals have special tools to find all rat entrances and can clean dangerous contamination correctly.

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