Rodent Control for Roof Rats, House Mice and Pack Rats

Roof rats in the Phoenix area

Roof rats have been common in the Valley since the early 2000s. They were first reported in older Phoenix neighborhoods with mature citrus trees and have since spread across much of the metro area. Our post on roof rats in the Phoenix Valley goes into more detail.

A roof rat is slender and brown to black, with large ears and a tail longer than its head and body. It climbs well and nests off the ground, in citrus trees, in the dead fronds of palm trees and in attics.

Roof rats travel along the tops of block walls, on utility lines and through branches that touch the house. They get into attics through gaps at the roofline, the open ends of roof tiles at the eaves and openings around vents and pipes. An adult can squeeze through a gap about 1/2 inch wide. Around the yard they eat citrus, pet food and bird seed, and they chew drip lines for water.

House mice in garages and kitchens

House mice are small and gray-brown, about 3 inches long without the tail. They nest in garages, wall voids, stored boxes and the space under kitchen appliances. Mice come in under worn garage door seals, around pipes and through gaps as small as 1/4 inch. They breed quickly, so a few sightings can mean a larger population out of view.

Pack rats near the desert edge

Pack rats, also called wood rats, are native desert rodents with big ears and a furry tail, unlike the scaly tail of a roof rat. They are most common on lots near open desert in places such as Apache Junction, Gold Canyon and San Tan Valley.

Their nests are large piles of sticks, cactus pieces and debris, built at the base of prickly pear and cholla, under sheds, in woodpiles and inside vehicles that sit unused. Pack rats chew the wiring in cars, RVs, boats and equipment, and the repairs can be expensive. Clearing brush piles, stored lumber and debris away from the house and parking areas leaves them fewer places to nest.

Signs of rodents in and around the house

Rats and mice are active mostly at night, so homeowners usually find the evidence before they see an animal. Common signs include:

• Droppings along walls, in cabinets, in the garage or in the attic, about 1/4 inch long for mice and 1/2 inch with pointed ends for roof rats
• Gnaw marks on wood, plastic, wiring or stored boxes, which look light-colored when fresh
• Scratching or scurrying in the attic or walls at night
• Citrus hollowed out on the tree with the empty rind still hanging
• Grease marks, the dark smudges rodents leave along walls, beams and the edges of holes they use
• Chewed drip lines and emitters, or leaks with no obvious cause
• Stick piles near shrubs, sheds or parked vehicles, which point to pack rats

What professional rodent control includes

Trapping removes the rodents already in the house, but new ones will keep using the same openings until they are sealed. For that reason the technician points out every entry point the inspection turns up, so the homeowner knows which openings to close.

1. Inspection. We check the roofline, tile eaves, vents, pipe and wire openings, garage door seals, the attic and the yard, and note droppings, rub marks and travel routes.
2. Trapping. Traps go in the attic, the garage and along travel routes, out of reach of children and pets.
3. Sanitation. We point out food and shelter on the property, such as fallen fruit, pet food, woodpiles and untrimmed palm fronds.
4. Sealing advice. The technician points out the openings rodents are using, such as gaps at the roofline, tile eaves and vents, and notes which repairs a homeowner can make. Sealing should wait until trapping has cleared the attic, so no rats are shut inside.
5. Follow-up. Return visits cover trap checks, removal of what has been caught and a look for fresh droppings or gnawing. The job is done when the traps stay empty and no new signs turn up.

Health and property risks from rats and mice

Most rodent damage around Valley homes is to property. Rats and mice chew electrical wiring in attics and garages, which can create a fire risk, and they tunnel through and soil attic insulation. Their droppings and urine contaminate food and stored items, so anything they have gotten into should be cleaned or thrown out.

Hantavirus is rare in Arizona, and it is carried mainly by deer mice rather than the roof rats and house mice found in most Valley homes. Public health agencies still recommend a careful method for cleaning up any rodent droppings:

1. Open doors and windows and let the area air out for at least 30 minutes.
2. Put on rubber, latex or vinyl gloves.
3. Spray droppings and nesting material with a disinfectant or a mix of 1 part bleach to 10 parts water, and let it soak for 5 minutes.
4. Wipe everything up with paper towels, bag them and put the bag in the trash.
5. Disinfect the area, then wash the gloves before taking them off and wash your hands with soap and water.

Yard habits that keep rats away

Sealed entry points keep rodents out of the house, and a few changes in the yard give them less reason to stay nearby:

• Pick up fallen citrus and harvest ripe fruit promptly.
• Bring pet food in at night and clean up spilled bird seed.
• Trim trees, shrubs and vines so they don't touch the roof or walls.
• Have dead fronds removed from palm trees.
• Store firewood, lumber and boxes off the ground and away from the house.
• Repair leaking drip lines and hose bibs.

Rodent jobs usually take several visits. To get started, request a free inspection or call (480) 518-1942. For digging animals in the lawn, see our page on gopher control.