By Matt Roy, Independent Newsmedia
As predictable as the spring citrus bloom, perennial rat fears blossom again in the Sun Cities.
Gloria Bonnert noticed the pitter-patter of tiny feet in the attic of her Sun City home last month and is taking steps to deal with the pest.
“I heard something in the attic and it’s keeping me awake at night,” Ms. Bonnert said.
Having initially called the Maricopa County Health Department, she said the agency offered little assistance for her problem.
“I called the county health department and they came out and saw the damage. They then left a pamphlet in the screen door,” she said. “I was so disappointed.”
Ms. Bonnert sought help from a national exterminating firm to eradicate the pests, which they told her is a hybrid of the roof rat and the indigenous local species, knows as the pack rat or wood rat. The exterminator made the same claim to TV news media in 2015, which was widely reported though, even to their own admission, not supported by science.
Randy Babb is a biologist with the Arizona Game & Fish Department who says hybridization of the species is unlikely and that native species are enough of a concern on their own.
“There is no biological evidence of what they’re claiming,” Mr. Babb said. “They are two different genera. The pack rat is Noetoma, while the roof rat are of the genus Rattus. Basically, these animals are as closely related as we are to chimps. We’re in the same family but of a totally different genera.”
He said even if interbreeding did occur, such unions would produce sterile offspring. That said, the critters described in the prior reports are consistent with the native species, which is itself a valid concern and can be a serious problem for homeowners. Though the wood rat is unlikely to nest above ground, the species is highly adaptable and could easily forage in attics, if given access.
“Wood rats forage in a range 50 to 75 yards from their nests. They will get up in an attic or roof and are well known for climbing in engine compartments of vehicles,” Mr. Babb said, adding that his car had been damaged by the pest at his home in the East Valley.
The two species are easy to discern, he said, with the native rat having what he described as an “actually beautiful” coat of fur, large ears and a shorter, furry tail. By contrast, the alien roof rat is darker and larger, with a pointed snout, smaller ears and a longer tail, which is scaly and nearly hairless.
Though the latter rat is an especially adept climber — capable of climbing poles and tight-roping power lines onto a home’s roof — the local rats are decent tree climbers and will seek out food and shelter wherever they can find it and leaving destruction in their wake, he said.
“They can be incredibly damaging, building big elaborate nests and causing problems,” Mr. Babb said. “They are chronic chewers and can chew even wiring in cars and trucks. Even though they may be a nuisance, they realty aren’t a threat to people.”
Roof rats get a lot of attention and generate fear among resident, both because of the destruction they cause and the diseases they are known to carry, including the plague attributed to the Black Death in Medieval Europe. The local species, though also damaging and disease-carrying, is also an important part of the environment.
“Wood rats are a part of our native fauna and a valuable, important part of our ecosystem,” Mr. Babb said.
A typical attic space this year will see temperatures in excess of 140 degrees, far more than any mammal can endure, he added.
“No mammal could survive those temperatures,” he said.
Wood rats prefer to nest below ground where temperatures — even in the summer’s hottest days — hover around 80 degrees. But a well-ventilated attic could provide needed shelter or desirable nesting materials. The best thing homeowners can do is limit access to their roof or attic by trimming back tree branches adjacent to the house and having the roof vents covered in a steel mesh with openings no larger than a quarter-inch, Mr. Babb said.
Dawn Gouge, a professor specializing in public health pests at the University of Arizona Maricopa Agricultural Center, also questioned the notion of a hybrid native-nonnative rat, but suggested either species can be a problem.
“There is no scientific evidence to support the hybrid rat theory and the few I have investigated turned out to be roof rats or pack rats, not a hybrid,” Ms. Gouge stated by email.
That being said, Ms. Gouge acknowledged either species can be an annoyance.
“Commensal rodents (house mice, roof rats and Norway rats) cause 8 percent of all house and building fires in the U.S. The roof rat is implicated in the transmission of a number of disease-causing pathogens to humans, including rat-bite fever, leptospirosis, murine typhus, salmonellosis and plague. Domestic animals can also be impacted and ectoparasites (fleas, ticks, rodent mites). But our native pack rats can also cause electrical fires and carry ectoparasites,” she stated.
Ms. Gouge said homeowners can watch for signs of rat activity, including droppings, smudge marks, nests, urine odors, gnaw marks or scraping and scampering noises in walls and attics. Household pets, with their keener senses, may notice the pests first.
“Pets often know they are there before we do,” she added.
Prevention and eradication
Barry Paceley is an Arcadia resident and often-quoted expert on roof rats since the rodents first appeared in that Phoenix neighborhood around the turn of the century. His website, www.roofrat.net, offers plenty of advice for eliminating and controlling all types of rats. Among the best choices for eradication are snap traps and poison bait stations, according to the site.
“Snap traps (like those used for mice) are intended to be baited with a food source and to kill the rat as the rodent attempts to eat the bait. These traps must be emptied of the dead rodent and reset after each use. They are recommended for use only in areas where bait stations are not feasible, such as inside the home,” according to the website.
A better choice is the personal use bait station or a commercial bait station, both of which are designed to kill rats while protecting children, pets and wild birds from accidental poisoning.
For those who employ live traps, captured rodents must be exterminated and not moved to other properties or areas around the Valley. Maricopa County Vector Control may pick up and dispose of captured live rats on request, if staffing permits. Residents can reach them at 602-506-6616.
Homeowners can also take steps to prevent infestations on their property by trimming back bushes and trees, gleaning fruit trees and keeping fruit off the ground, and securing pet food and water sources, according to Mr. Paceley’s website.
Ms. Bonnert said she is happy with her exterminator and the work they are doing on her property, having already sealed access points and laid traps in the attic, which can take time to be affective, since rats may inherently distrust newly placed items in their environment. She expects the problem to be resolved soon, she said.
“I think I picked the best company to work with,” Ms. Bonner said.
For other Sun Cities residents seeking professional pest help, both PORA and SCHOA offer resources to help their members choose a reputable exterminator or home improvement contractor.
“Yes, rats are always a big concern in Sun City,” stated SCHOA Director Carole Studdard by email. “When receiving calls from residents who are concerned about their safety regarding rats, we refer them to pest control companies that are members of our preferred business partner program.”
The referral program provides its members in Sun City with a database of more than 350 participating vendors working in a variety of service categories. Those vendors must pass a background check, which includes verification of references, as well as review of state licenses and filing with the Better Business Bureau. Residents provide feedback on the services received.
The Consumer Referral Services Department at PORA offers a similar service to Sun City West residents, who may call 623-214-1646 to receive three or four references for qualified vendors or contractors. Participating businesses must pass a rigorous due diligence process, including verification of five references, scrutiny of bonding and licensing, proof of liability and workers’ compensation insurance and status with BBB.
Though SCHOA and PORA can offer no guarantees, vendors with unresolved complaints are removed from the referral list.
Visit www.porascw.org or www.suncityhoa.org.