RAT IDENTIFICATION & RODENT EXTERMINATION
People don’t often see rats, but signs of their presence are easy to detect, so you know just when you need to call in the rodent exterminator. In California, the most troublesome rats are two introduced species, the roof rat and the Norway rat. It’s important to know which species of rat is present in order to choose effective control strategies.
Norway rats, Rattus norvegicus, sometimes called brown or sewer rats, are stocky burrowing rodents that are larger than roof rats. Their burrows are found along building foundations, beneath rubbish or woodpiles, and in moist areas in and around gardens and fields. Nests can be lined with shredded paper, cloth, or other fibrous material. When Norway rats invade buildings, they usually remain in the basement or ground floor making them somewhat easier to clear out for the rodent exterminator. Norway rats live throughout the 48 contiguous United States. While generally found at lower elevations, this species can occur wherever people live.
Roof rats, R. rattus, sometimes called black rats, are slightly smaller than Norway rats. Unlike Norway rats, their tails are longer than their heads and bodies combined. Roof rats are agile climbers and usually live and nest above ground in shrubs, trees, and dense vegetation such as ivy. In buildings, they are most often found in enclosed or elevated spaces such as attics, walls, false ceilings, and cabinets. The roof rat has a more limited geographical range than the Norway rat, preferring ocean-influenced, warmer climates. In areas where the roof rat occurs, the Norway rat might also be present. If you are unsure of the species, look for rats at night with a bright flashlight, or trap a few before you call the rodent exterminator. The illustrations above show some of the key physical differences between the two species of rats, whileTable 1 summarizes identifying characteristics.
Among the diseases rats can transmit to humans or livestock are murine typhus, leptospirosis, salmonellosis (food poisoning), and rat bite fever. Plague is a disease that both roof and Norway rats can carry.
Hantavirus: Hantaviruses are negative sense RNA viruses in the Bunyaviridae family. Humans may be infected with hantaviruses through urine, saliva or contact with rodent waste products. Some hantaviruses cause potentially fatal diseases in humans, such as hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS), but others have not been associated with known human diseaseHuman infections of hantaviruses have almost entirely been linked to human contact with rodent excrement
Murine: Murine typhus (also called endemic typhus) is a form of typhus transmitted by fleas ( Xenopsylla cheopis ), usually on rats. Murine typhus is an under-recognized entity, as it is often confused with viral illnesses. Most people who are infected do not realize that they have been bitten by fleas. Symptoms of endemic typhus include headache, fever, muscle pain, joint pain, nausea and vomiting. 40–50% of patients will develop a discrete rash six days after the onset of signs.Up to 45% will develop neurological signs such as confusion, stupor, seizures or imbalance. Endemic typhus is highly treatable with antibiotics.
Leptospirosis: (also known as Weil’s syndrome, canicola fever, canefield fever, nanukayami fever, 7-day fever, Rat Catcher’s Yellows, Fort Bragg fever, black jaundice, and Pretibial fever) is caused by infection with bacteria of the genus Leptospira and affects humans as well as other animals. Leptospirosis is among the world’s most common diseases transmitted to people from animals. The infection is commonly transmitted to humans by allowing water that has been contaminated by animal urine to come in contact with unhealed breaks in the skin, the eyes, or with the mucous membranes. Flu like symptoms.
Rat-bite fever is an acute, febrile human illness caused by bacteria transmitted by rodents, rats or mice in most cases, which is passed from rodent to human via the rodent’s urine or mucous secretions. Alternative names for rat bite fever include streptobacillary fever, streptobacillosis, spirillary fever, and epidemic arthritic erythema. It is a rare disease spread by infected rodents and can be caused by two specific types of bacteria. Most cases occur in Japan, but specific strains of the disease are present in the United States, Europe, Australia, and Africa – one of the many hazards of being a rodent exterminator. Some cases are diagnosed after patients were exposed to the urine or bodily secretions of an infected animal. These secretions can come from the mouth, nose, or eyes of the rodent. The majority of cases are due to the animal’s bite. It can also be transmitted throughout food or water that is contaminated with rat feces or urine. Rats are not the only type of animal that can be infected with this disease. Others include weasels, gerbils, and squirrels. Household pets such as dogs or cats that are exposed to these animals can also carry the disease and infect humans. If a person is bitten by a rodent, it is important to quickly wash and cleanse the wound area thoroughly with antiseptic solution to reduce the risk of infection.
Rats eat and contaminate foodstuffs and animal feed. They also damage containers and packaging materials in which foods and feed are stored. Both rat species cause problems by gnawing on electrical wires and wooden structures such as doors, ledges, corners, and wall material, and they tear up insulation in walls and ceilings for nesting.
Norway rats can undermine building foundations and slabs with their burrowing activities and can gnaw on all types of materials, including soft metals such as copper and lead, as well as plastic and wood. If roof rats are living in the attic of a residence, they can cause considerable damage with their gnawing and nest-building activities. They also damage garden crops and ornamental plantings.
1/3 of all electrical fires are a result of rodents. If you suspect you have an infestation, call in the rodent exterminator.
Step 1 Inspection
Step 2 Sanitation
Sanitation is fundamental to rat control and must be continuous. If sanitation measures aren’t 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 rats 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 also will make their detection easier. Collect garbage, trash, and garden debris frequently, and ensure all garbage receptacles have tight-fitting covers. Where dogs are kept and fed outdoors, rats can 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 or you’ll eventually find yourself in need of the rodent exterminator.
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 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 one another and from buildings by a distance of 2 feet or more to make it more difficult for rats to move between them.
Step 3 Clean Out
Step 4 Exclusion
The most successful and long-lasting form of rat control in structures is exclusion, or “building 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, in order to exclude both rats and house mice. Kilter makes 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. Norway and roof rats are likely to gnaw away plastic sheeting, wood, caulking, and other less sturdy materials.
Because rats and house mice are excellent climbers, openings above ground level must also be plugged. Rodent proofing against roof rats, because of their greater climbing ability, usually requires more time to find entry points than for Norway rats. Roof rats often enter buildings at the roofline, so be sure that all access points in the roof are sealed. If roof rats are traveling on overhead utility wires, contact a rodent exterminator or the utility company for information and assistance with measures that can be taken to prevent this.
Step 5 Trapping/Removing
Because of the nature of the RODEX system there are usually Rats left behind or trapped inside the home. After the first steps of RODEX are completed we will leave behind traps to capture those inside. We never use baits because the rodent could die in a wall void and cause a stench.