Roof Rat Control

The Roof Rat (Rattus rattus) is the major problem species in the urban areas of Kern County. It is also known as the Tree Rat, Fruit Rat or Black Rat. This agile rat is slender with the tail longer than the head and body combined. Roof Rats frequently enter buildings and are also excellent climbers who can move about neighborhoods by using utility lines and fences as runways.

The Roof Rat prefers to feed on fruit often grown in residential backyards such as oranges, grapefruit, lemons, tomatoes, apricots and also nuts such as walnuts, pecans and almonds. Rats will also feed on pet food, snails, bird seed, chicken feed and grains.

Roof Rats will nest in large overgrown ivy patches, piles of lumber and firewood, untrimmed palm trees and yucca plants. They may also be found nesting in old furniture, abandoned cars, sheds and inside buildings. Rat survival and prosperity is dependent upon the existence of three basic environmental conditions: food, water and suitable harborage. Sanitation, good housekeeping and harborage removal are the first steps in a successful rat control program.

The homeowner can help control rat populations by doing the following:

  • Harvest oranges, grapefruit, apricots, plums, nuts, tomatoes, etc. as soon as they are ripe. Pickup up all fruit that has fallen on the ground.
  • Never leave uneaten pet food outside overnight. Keep pet food in sealed, metal containers if stored in the garage or other outbuildings
  • Keep plum trees and yucca plants well-trimmed. Algerian ivy, oleander, bougainvillaea, jasmine and other thickly matted plants should be periodically thinned and trimmed well away from roofs, walls, fences, utility poles and trees.
  • Store wood and lumber piles on racks at least 18 inches above the ground and 12 inches away from walls.

Rats can enter a home through small exterior openings of less than one inch in diameter. Important steps a homeowner can take to exclude rats are inspecting and repairing:

  • Basement windows and ventilation ports
  • Attic vents and louvers
  • Gaps between roof and chimney
  • Vent pipes and shafts
  • Tile roofs along the eaves

All access openings should be screened with 1/4 inch galvanized hardware cloth and inspected at least once a year for condition. Gaps around pipes and electrical conduits should be sealed. Tree limbs should be kept well away from the eaves, roof and exterior walls of the house

The District is not involved in the control of mice, squirrels, gophers, or other rodents. If homeowners require control of these pests, private pest control companies should be contacted.