Frigid Temperatures Drive Rodents Indoors

Terminix identifies most rodent-infested cities

Shaping up to be one of the coldest winters in memory, the recent polar vortex is driving both people and rodents indoors. Today, Terminix, the world’s largest pest control provider, released its list of most rodent-infested cities, with San Francisco taking the top spot. 

Based on Terminix call volume, the most rodent-infested cities include:

1. San Francisco, CA

2. Detroit, MI

3. Chicago, IL

4. Philadelphia, PA

5. Dallas, TX

6. Boston, MA

7. Los Angeles, CA

8. Denver, CO

9. Houston, TX

10. Baltimore, MD

Terminix created the list by compiling and analyzing rodent-specific call volume to its more than 300 branches throughout the country. The rankings represent cities with the greatest call volume for the period of November 1, 2013 through January 24, 2014. Eight of the top 10 markets listed have experienced several waves of bitterly cold arctic air this winter, causing rodents to look for warmth in homes. 

While San Francisco and Los Angeles haven’t had the same cold weather as the other parts of the country, these port cities consistently rank high in rodent activity. Ships can be perfect harborages for rodents with plenty of stored foods, hundreds of nooks and crannies, and no natural predators to keep them away. Additionally, docks and bays are ideal natural habitats for rodents with an abundance of food options including fish, crustaceans, and birds.

“Rodents are a serious public health threat and can transmit a variety of diseases to humans via droppings and bites,” said Stan Cope, PhD and entomologist with Terminix. “Indirectly, other pests such as ticks, mites and fleas can carry diseases from rodents to humans.”

Rodents look for shelter when the temperatures drop and seek refuge in attics, garages, basements, kitchens, walls, and other warm places in homes. Beyond just a nuisance, rats and mice can spread more than 35 diseases, trigger allergies and asthma attacks, and cause property damage and house fires by chewing drywall and electrical wires.

The presence of rodents in the home should be taken very seriously. Rats and mice are known to carry pathogens which may be spread through food contamination, bites, or their excrement. Additional health concerns include:

* Strep, staph and Salmonella, as well as parasites like ticks, fleas and lice

* Mice dribble urine constantly and can drop up to 25,000 fecal pellets each year

* Mouse allergens are found in 82 percent of American homes

* Rodents cause up to 25 percent of house fires in the US every year because of chewed wiring

Because nearly all infestations begin outside a building, rodent-proofing exclusion services are the best option to prevent access into the home in the first place. Rats need only a hole the size of a quarter to enter, while mice can squeeze through a crack the width of a pencil. Large openings (including around pipes, soffit vents and cables) should be stuffed with steel wool/wire mesh before sealing with caulk or expanding foam, otherwise rodents could chew through to enter. Exclusion also properly seals foundation vents and crawlspace openings to prevent rodent entry.

Terminix offers the following tips to help prevent and control rodent activity in the home: 

* Seal all cracks in the home’s exterior, especially on the southern and western walls.

* Ensure attic and foundation vents are equipped with tight-fitting ¼ inch hardware cloth.

* Move piles of firewood, leaf piles, and mulch away from home’s foundation. These can provide ample sources of shelter for rodents.

* Trim tree branches 6 to 8 feet away from the home. Rodents are great climbers and acrobats, allowing them to scale rough surfaces in order to access the home’s roof and exterior vents.

* Install a tight-fitting weather strip on the bottom of all windows and doors, including garage doors.

* Contact a Terminix professional about exclusion services that will help prevent rodent activity.