The best strategies to keep rodents away are removing food, shelter and access, and then using traps.
Clean up kitchen floors daily and keep food in airtight containers that rats cannot gnaw through.
Boxes or piles of belongings should not be stored on the floor near walls.
Don't leave pet food out for long, and keep birdseed, chicken feed, fallen nuts and fruits, and garbage off the ground outside.
Firewood should be at least 18 inches off the ground and plants at least 3 feet away from the foundation.
Rodents can pass through holes larger than a 1/4 inch, and rats can chew small holes into large ones. Cover all entry points into or under your home and outbuildings, including unscreened crawl space openings, vents and window gaps, pet doors, gaps in garage doors and around pipes or wires entering walls, and uncapped floor drains. Seal holes with sheet metal, screening, wood or caulk before mice and rats seek shelter from cold autumn weather.
Keep garbage cans and yard waste bins shut tight (bungee cords can help).
If you compost, use a rodent-resistant bin with a lid, floor and no holes or gaps larger than 1/4 inch.
Tips for traps
There are many types of rodent traps, including snap, glue, multiple catch and electronic. Snap traps are recommended over all others.
Glue boards or sticky traps are not recommended as they are cruel, they catch small wildlife indiscriminately, and rodents often will squeal until they die or are killed.
Multiple-catch non-lethal traps are also not recommended since they do not kill the mice and hence require euthanizing.
Place traps against a wall or other vertical surface, and in the areas you have seen the rodents or their droppings.
For roof rats, securly attach traps to ledges, branches or other places you see the rats traveling.
Place snap traps so rodents are likely to run directly over the trigger. Put multiple traps out – a dozen is not too many – and place them in pairs end to end or with triggers toward the wall so rodents can't jump over them easily.
To protect pets and children from snap traps, put traps in secure trap enclosures. Small cardboard boxes with holes cut on either end can work, but are less effective.
Attractant for snap traps
Use different types of attractant on different traps at the same time: peanut butter, cheese, bacon, crackers, etc.
About poison baits
The use of poison baits creates serious health risks to children and pets and can impact wildlife predators of rodents. Therefore, poison baits should only be used when necessary, which is typically only when there is a very large population of rodents and in a sensitive area. Professional pest management is recommended in those cases. Any poison bait that is exposed or uncovered is particularly dangerous to children and to wildlife.
Disposal of dead rodents
Dispose of dead rodents in a plastic bag in the trash. Wear disposable gloves when cleaning up rodent feces – feces can transmit some diseases. Do not vacuum or sweep them up. Instead, douse them with a 10 percent bleach solution and let stand for at least 20 minutes. Then use newspaper, paper towels or rags to wipe droppings up. Bag up and dispose of everything, including gloves, in the trash. Wash hands and clothing.
For serious rodent infestations, call a professional.
Look for a certified prevention-based, least-toxic company. Tip: Recurring problems with rats could be a sign of a sewer line break. Call your county vector control office or Extension Service for specific instructions.