Rodent Prevention: The Clean, Seal, Trap Program

1CLEAN: Eliminate Food and Nesting Sources

Rodents need food, water, and shelter within 25–50 feet of their nesting site. Removing these resources is the foundation of any long-term rodent program. A single missed food source — a birdseed spill, an open compost bin — can sustain an entire colony.

• Store all trash and garbage in rodent-proof, watertight containers with tight-fitting lids
• Use squirrel guards on bird feeders; move feeders at least 20 feet from the structure
• Cut and remove grass and weed overgrowth — rodents use tall vegetation as runways
• Remove old vehicles, tires, and debris piles that provide shelter
• Elevate hay, woodpiles, and garbage cans at least 1 foot off the ground
• Keep pet food indoors in sealed containers; clean up pet waste frequently
• Position compost bins 100+ feet from the house; stop adding food waste if rodents are present
• Harvest fruit and vegetables promptly; do not leave produce on the ground

2SEAL: Block Every Entry Point

Sealing entry points is the most permanent component of rodent exclusion. Mice can squeeze through a hole the size of a nickel (¼ inch); rats require only a hole the size of a half-dollar (½ inch). Any gap, crack, or penetration — no matter how small — must be sealed with materials rodents cannot chew through.

• Inspect: kitchen cabinets, refrigerators, stoves, floor corners, closets
• Inspect: fireplace dampers, doors, windows, and their frames
• Inspect: pipes under sinks and washing machines, hot water heater and furnace connections
• Inspect: floor vents, dryer vents, attic vents, and crawl space screens
• Inspect: utility penetrations — electrical, plumbing, cable, and gas line entries
• Fill small holes (< ½ inch) with steel wool secured with caulk
• Fix large holes with hardware cloth (½-inch galvanized), lath metal, cement, or metal sheeting
• Cover burrows and sink holes outside with packed dirt and monitor regularly

3TRAP: Reduce Existing Populations

Trapping is used to eliminate rodents already inside the structure after sealing. It is not a standalone solution — trapping without exclusion simply removes the current population while new rodents continue to enter.

• Choose snap traps or glue boards (recommended over rodenticide to prevent carcass odors)
• Place traps perpendicular to walls, with the trigger touching the wall surface
• Set traps wherever there is evidence of activity: droppings, gnaw marks, runways, or nests
• Bait with peanut butter, chocolate, or nesting material (cotton or dental floss)
• Check traps daily and dispose of catches promptly in sealed bags
• Use multiple traps simultaneously — rodents quickly learn to avoid repeatedly disturbed traps
• Avoid rodenticide (poison bait) indoors: rodents die inside walls and create odor problems

4Signs of a Rodent Infestation

Early detection prevents large infestations. Learn to recognize the signs:

• Droppings: small, dark, rice-shaped (mouse) or capsule-shaped (rat) pellets near food or along walls
• Gnaw marks: wood, plastic, wiring insulation — fresh marks are lighter in color
• Tracks: dusty footprints or tail drag marks along baseboards and in attics
• Nests: shredded paper, insulation, or fabric in dark, undisturbed areas
• Scratching sounds: movement inside walls or ceiling, especially at night
• Foul odor: persistent musky smell, especially in enclosed spaces
• Grease marks: smudges along walls and pipes where rodents repeatedly travel

5When to Call a Professional

DIY rodent control is appropriate for minor, early-stage activity. Professional intervention is warranted when: the infestation has penetrated the structure (walls, attic, crawl space), multiple entry points exist that require exclusion work, snap trap and glue board programs fail to reduce activity within 2 weeks, or the property is adjacent to agricultural land with persistent rodent pressure.