5 Tips to Keep Rats Out of Your Home

Unless they’re a pet and you’ve given them a name, nobody wants rats or rodents skittering around their homes, scaring them at night, creeping them out by day and maybe even making them sick.

But it can happen easier than you think. A rat can squeeze through a hole as small as a quarter to get into a home, garage, cabin or workshop. Mice can squeeze through a hole no bigger than a dime!

Private pest companies provide rat-control services. But the County Department of Environmental Health’s Vector Control Program does conduct outdoor inspections, helps homeowners pinpoint the source of infestations, provides rat-control starter kits and expert instructions on how to control rodents to county residents for free.

Rodents are vectors, animals that can transmit diseases to people. Rats can carry plague, cause rat-bite fever or carry tapeworms; some wild mice can carry hantavirus. Even when they’re not carrying disease, rats can make people sick if people eat food that’s been contaminated by rodent urine or droppings. They can also damage homes by gnawing insulation, wood and wiring and defecating up to 60 times a day.

How do you know if you have rats? Here are some signs to watch out for: sounds in your attic, floors and walls; rat droppings in garages, storage buildings and other sheltered areas; damaged food containers or food; signs of gnawing; bark stripped from trees and shrubs.

Fortunately, you can help protect your home and property. Above all, remember, rats can’t live without food, water or shelter.

Here are five handy rat-proofing tips:

Find and Seal Up Holes

Find and seal all external holes in homes, garages, cabins and sheds to keep rats and rodents from getting in. Use rodent-proof materials to make repairs: ¼ inch 18-22 gauge wire hardware cloth. Also install metal weather stripping under doors to remove gaps.

Keep the Pet Food in at Night

Don’t leave pet food or bird seed out at night. It’s an open invitation for rats and rodents. Feed pets during daylight hours and remove uneaten food immediately.

Pick Up After Your Fruit Trees, Vegetable Gardens

If your yard has fruit trees, nuts or vegetable gardens, make sure you pick food as it ripens. Don’t leave fallen fruit or vegetables lying on the ground; throw it out or compost it.

Keep Tree Branches Away From Your Roof

Trim tree branches away from your roof. Roof rats are the most common type in San Diego County. They like to climb, and can crawl across tree limbs to your roof.

Keep it Clean

Properly bag and get rid of litter, trash and debris.

For more information, contact the County Vector Control Program at (858) 694-2888 or For more information about rats, go to the Department of Environmental Health’s page on rats, or watch the County’s “Got Rats?” video.



Gig Conaughton is a communications specialist with the County of San Diego Communications Office. Contact