Roof Rat Removal

The roof rat can transmit various diseases to humans, including salmonellosis, leptospirosis, murine typhus, rat-bite fever and plague. It can also transmit disease to pets. Roof rats eat human and pet foods, contaminating them. They also gnaw electrical cables, creating a fire hazard. They use insulation to build their nests and eat plants in the garden. They often enter buildings through the roof. Several methods can remove roof rats from your property and prevent them from creating damage or posing safety risks.

Things You'll Need

• 1/4-inch wire mesh
• Sheet metal, 18 to 24 inches wide
• Peanut butter, nutmeats, fruits or gumdrops
• Snap traps
• Gloves
• Plastic bags

Instructions

Habitat Modification

1. Remove possible food sources to make the area less attractive to roof rats. Store materials in rodent-proof containers and use rodent-proof garbage bins. If you grow fruit plants in your garden, harvest them as soon as they are ready and remove fallen fruits immediately. Bring pet food, bird feeder and containers of water inside because water can attract rats.

2. Remove items that can provide cover for roof rats. They tend to be shy, and lack of cover makes the area unattractive to them. Prune shrubs and trees to clear the space below them. Mow, trim or remove ground cover plants above 1 foot in height. Store items at least 1 foot away from walls and fences and at least 18 inches above the ground.

3. Eliminate the items that roof rats can use for travel, including vines, branches, fences and wires. Prune back vines on buildings and fences and prune trees to prevent the branches from touching other materials. Remove tree branches that hover above the roof.

Exclusion

1. Inspect the exterior walls of the building for openings with a diameter of 1/2 inch or larger, because roof rats can squeeze through them. Focus on the roof and the roof line. Seal these openings with steel or copper wool, concrete mortar or metal flashing.

2. Install 1/4-inch wire mesh or heavy wire screen on attic and foundation vents.

3. Wrap a piece of sheet metal about 18 to 24 inches in width around trees and walls to prevent roof rats from climbing them. Locate the sheet metal 4 feet above the soil and above areas from where the rat can jump.

Trapping

1. Place peanut butter, nutmeats, fruits or gumdrops on snap traps without setting the traps. This allows the rats to get accustomed to eating from the traps and helps you note the feeding areas of the rats. Repeat this every day for about one week.

2. Set the traps and place them along the rats' usual pathways, which frequently include overhead beams, pipes, ledges and sills. Do this at dusk, because roof rats come out at night. This prevents you from accidentally trapping nontarget animals such as squirrels and birds.

3. Inspect all the traps in the morning and discard any caught roof rats. Wear disposable gloves, place the carcasses and gloves in a plastic bag, place the plastic bag in another plastic bag and dispose of it in an outdoor garbage bin.

Tips & Warnings

• Place outdoor traps in bait stations to prevent them from affecting nontarget animals. A bait station has a size that is only big enough to accommodate rats.

• Use nails, rubber band or duct tape to secure traps when you place them in places with no stable horizontal surface.

• You can use glue boards instead of snap traps.

• Poison baits can work as an alternative to snap traps, but the rats sometimes die in inaccessible areas, producing a nasty odor and attracting insects.

• Electronic devices that claim to produce high-frequency sounds to frighten rats away don't work, because rats quickly accustom themselves to repeated sounds.

• Chemical repellents don't work to keep roof rats away.

References

• The University of Arizona Cooperative Extension: Roof Rat Control around Homes and Other Structures
• Internet Center for Wildlife Damage Management