Rat Management

MANAGING A RAT PROBLEM
Three elements are necessary for a successful rat management program: sanitation measures, building construction and rodent proofing, and, if necessary, population control.

Sanitation
Sanitation is fundamental to rat control and must be continuous. If sanitation measures are not properly maintained, the benefits of other measures will be lost, and rats will quickly return. Good housekeeping in and around buildings will reduce available shelter and food sources for Norway and, to some extent, roof rats. Neat, off-the-ground storage of pipes, lumber, firewood, crates, boxes, gardening equipment, and other household goods will help reduce the suitability of the area for rats and will also make their detection easier. Garbage, trash, and garden debris should be collected frequently, and all garbage receptacles should have tight-fitting covers. Where dogs are kept and fed outdoors, rats may become a problem if there is a ready supply of dog food. Feed your pet only the amount of food it will eat at a feeding, and store pet food in rodent-proof containers.

For roof rats in particular, thinning dense vegetation will make the habitat less desirable. Climbing hedges such as Algerian or English ivy, star jasmine, and honeysuckle on fences or buildings are very conducive to roof rat infestations and should be thinned or removed if possible, as should overhanging tree limbs within 3 feet of the roof. Separate the canopy of densely growing plants such as pyracantha and juniper from each other and from buildings by a distance of 2 feet or more to make it more difficult for rats to move between them.

Building Construction and Rodent Proofing
The most successful and long lasting form of rat control in buildings is to "build them out." Seal cracks and openings in building foundations, and any openings for water pipes, electric wires, sewer pipes, drain spouts, and vents. No hole larger than 1/4 inch should be left unsealed to exclude both rats and house mice. Make sure doors, windows, and screens fit tightly. Their edges can be covered with sheet metal if gnawing is a problem. Coarse steel wool, wire screen, and lightweight sheet metal are excellent materials for plugging gaps and holes. Plastic sheeting, wood, caulking, and other less sturdy materials are likely to be gnawed away.

Because rats (and house mice) are excellent climbers, openings above ground level must also be plugged. Rodent proofing against roof rats usually requires more time to find entry points than for Norway rats because of their greater climbing ability. Roof rats often enter buildings at the roof line area so be sure that all access points in the roof are sealed. If roof rats are travelling on overhead utility wires, contact a pest control professional or the utility company for information and assistance with measures that can be taken to prevent this.

Rodent Proofing Your Home
*Repair or replace damaged ventilation screen around the foundation and under eaves.
*Provide a tight fitting cover for the crawl space.
*Seal all openings around pipes, cables, and wires that enter through walls or the foundation.
*Be sure all windows that can be opened are screened and that the screens are in good condition.
*Cover all chimneys with a spark arrester.
*Make sure internal screens on roof and attic air vents are in good repair.
*Cover rooftop plumbing vent pipes in excess of 2 inches in diameter with screens over their tops.
*Make sure all exterior doors are tight fitting and weatherproofed at the bottom.
*Seal gaps beneath garage doors with a gasket or weatherstripping. *Install self-closing exits or screening to clothes dryer vents to the outside.
*Remember that pet doors into the house or garage provide an easy entrance for rodents.
*Keep side doors to the garage closed, especially at night.

Population Control
When food, water, and shelter are available, rat populations can reproduce and grow quickly. While the most permanent form of control is to limit food, water, shelter, and access to buildings, direct population control is often necessary.

For controlling rats indoors, use traps. Baiting is best done outdoors only, otherwise rats may die behind a wall. In hot weather, the stench of a dead rat can be unbearable and may necessitate cutting a hole in the wall to remove the carcass. Also, ectoparasites such as fleas and mites often leave dead rat carcasses and may infest the entire house if the carcass is not removed promptly.