Rodent Control: How to Get Rid of Mice and Rats and Keep Them Out

Rodents are more than a nuisance - they contaminate food, spread diseases (hantavirus, salmonella, leptospirosis), chew electrical wiring (causing house fires), and damage insulation, drywall, and stored items. A single pair of mice can produce 60+ offspring per year, so small problems become big problems fast.

Signs of Rodent Activity

Droppings: The most obvious sign. Mouse droppings are small (1/4 inch), dark, and rice-shaped. Rat droppings are larger (1/2-3/4 inch), dark, and banana-shaped. Fresh droppings are dark and moist; old ones are dry and crumbly. The location of droppings tells you where they're traveling. Gnaw marks: Rodents must constantly gnaw to keep their teeth from overgrowing. Look for gnaw marks on food packaging, wood, plastic, and especially electrical wiring. Sounds: Scratching, scurrying, and squeaking in walls, attics, and ceilings, especially at night. Rub marks: Greasy smear marks along walls and baseboards where rodents repeatedly travel.

Step 1: Eliminate the Current Population

Snap traps: The most effective and humane kill method for small infestations. Place traps perpendicular to walls (trigger end against the wall) in areas with droppings or activity. Use peanut butter as bait. For mice, place traps every 5-10 feet along active runways. For rats, every 15-20 feet. Check traps daily.

Bait stations (professional): Tamper-resistant stations containing rodenticide. More effective for larger infestations. Should be placed and monitored by a professional to ensure pet and child safety. Modern anticoagulant baits take 3-5 days to work, giving rodents time to return to the colony before dying.

What to avoid: Glue traps are inhumane and ineffective for anything beyond monitoring. Ultrasonic repellent devices have no scientific evidence supporting their effectiveness - don't waste your money. Poison placed without bait stations is dangerous to children, pets, and wildlife.

Step 2: Seal Entry Points (Exclusion)

This is the most important step and the one most homeowners skip. A mouse can fit through a gap the size of a dime (1/4 inch). A rat can fit through a gap the size of a quarter (1/2 inch). Common entry points include gaps around pipes and utility lines entering the home, gaps under doors (install door sweeps), foundation cracks and gaps where siding meets foundation, dryer vents and exhaust fan openings without proper screens, gaps around garage doors, and roof vents and soffit gaps.

Seal with steel wool and caulk for small gaps (rodents can't chew through steel wool), hardware cloth (1/4 inch mesh) for larger openings, metal flashing for gaps at the roofline, and expanding foam with steel wool embedded for pipe gaps. A thorough exclusion job by a professional costs $300-$1,000 but is the most effective long-term investment in rodent control.

Step 3: Eliminate Attractants

Store all food (including pet food) in sealed glass or metal containers. Fix water leaks and eliminate standing water. Keep garbage in sealed cans with tight-fitting lids. Remove bird feeders or use rodent-proof feeders. Clear vegetation and debris from against the foundation. Store firewood at least 20 feet from the house. A clean environment doesn't guarantee no rodents, but it reduces attractants that draw them to your property.

When to Call a Professional