Units Cover

Pests Under Fire: Best Practices for Pest-Proofing Your Community

By Missy Henriksen 

Click here to view the reprint. The article was published in the October 2012 edition of UNITS magazine.

According to the National Fire Protection Association (NFPA), “fire departments responded to 46,500 reported home structure fires involving electrical failure or malfunction in 2010. These fires resulted in 420 civilian deaths, 1,520 civilian injuries and $1.5 billion in direct property damage.”

These alarming statistics include fires treated in multifamily housing and, while the specific causes of such fires vary, it’s estimated that rodents are responsible for 20 percent to 25 percent of all fires of unknown caus- es because of their propensity for chewing electrical wiring and gas lines.

Recent news reports from Franklin, N.H., and Phoenix, Ariz., suggest electrical wiring damaged by rodents was to blame for fires in multifamily communities in these cities. With such overwhelming indication of the destructive nature of rodents, it is imperative facility managers take aggressive steps to keep rats, mice and other vermin out of their properties.

Types of Rodents

While no rodent is welcome in a home setting, there are certain species more likely than others to set up residence in an apartment building or complex. The house mouse is the most common rodent reported in residential settings. Treatment of house mice infestations can be particularly challenging in multifamily housing because of the vast amount of hiding space such structures offer to mice, the lack of consistent sanitary practices exercised by residents and, for some, the lack of or failure to adhere to a rodent control program. In addition, as house mice breed quickly, a small infestation can grow into a large problem if not addressed promptly.

Norway and roof rats are also known to infest multifamily dwellings. Despite what many believe or may want to believe, there is no neighborhood that is immune to rats—though urban areas are certainly more susceptible to invasions by these pests because of infrastructure issues such as old sewage systems, waste disposal practices, poor drainage, etc.

Harborage Spots

Like all living creatures, pests require food, water and shelter for their survival. Rodents are no exception. Their entrance into our personal space will be for any or all of these reasons. While most frequently problematic in the fall when temperatures drop and natural food sources become scarce, rodent activity takes place year-round.

House mice are known to enter buildings through:

  • Gaps surrounding utility pipes or clothes dryer vents;
  • Ground floor doors left ajar;
  • Garbage shoots; and
  • Cracks and crevices larger than 1/4 inch in a building’s structure.

Norway rats typically achieve entry through:

  • Gaps and cracks along building foundations;
  • Wood piles along buildings;
  • Cracks and crevices larger than 1/2 inch in building structures
  • Cluttered or garbage-filled alleys; and
  • Toilet bowl or uncapped drains (mostly in cities with large infestations in the sewer). system)

Roof rats, a species most often found in vegetation-rich neighborhoods older than 10 years, infiltrate communities through:

  • Apartment balconies, particularly those with pet food bowls or birdfeeders;
  • Trees and tall shrubbery; and
  • Improperly sealed attic vents.

Eliminating Entry

For multifamily community managers to rodent-proof their buildings, it is important to recognize the spots that provide easy access to rodents and attend to their elimination:

1. Trim tree branches to 6 feet back from the building.

2. Install door sweeps if door thresh- olds have a gap larger than 1/4 inch wide.

3. Seal dryer vents.

4. Seal cracks and crevices in building foundations, as mice can enter through holes the size of a dime.

5. Seal utility and electrical line holes to the outside.

6. Install metal rat guards around pipes.

7. For those in cities with heavy rat populations in the sewers, install rodent proof- ing devices in toilets to prevent rat entry.

8. Pest-proof vent openings.

9. Ensure fascia boards are tightly adjoined to the property structure.

10. Clean and maintain trash areas.

11. Prohibit residents from leaving pet food and birdfeed on balconies and discourage them from leaving human food out unattended, as well.

12. Ensure gutters and drainage systems are functioning properly and there are no back-ups.

While much of this advice is consistent with good upkeep and repair practices, these same steps go a long way in providing a protective barrier against rats and mice. It is important to eliminate the origin of rodent invasions, as mice will often leave a pheromone trail that will be used by future interlopers in identifying access locations. 

Rodent-Proof Wiring

As rodents can chew through critical wiring and cause an arc fault that, in turn, can cause a fire, the Consumer Product Safety Commission has addressed this problem by recommending the installation of Arc-Fault Circuit Interrupters (AFCIs) during construction. Many jurisdictions are now requiring AFCIs in new construction, as these circuit breakers can detect potentially dangerous arcs and disconnect power before a fire can start. 

Pest Control Plan

Because of the damage rodents (and other pests) can cause, as well as the diseases they carry and spread, it is important that property managers work with a pest management professional to prevent an infestation and address any current issues. Many pest management professionals will work with property managers to conduct a pest exclusion and analysis of conductive conditions, or a thorough Integrated Pest Management inspection.

Regarding rodent control, trained and licensed professionals will devote the necessary time and resources required to identify long-term solutions to mice and rat problems, not just control the immediate situation. For instance, they will look at historical infestations to determine pathways rodents may be using between apartments. They will create rodent sighting activity logs, complete thorough inspections, and provide ongoing monitoring. Of course, if there is an active infestation present, they will develop an appropriate control plan.

Working to keep multifamily facilities free from pests and the damage they can cause ultimately requires a partnership between property management, residents and the pest professional.

The NPMA, a non-profit organization with more than 7,000 members, was established in 1933 to support the pest management industry’s commitment to the protection of public health, food and property. For information about pests and prevention tips, please visit www.PestWorld.org.

The author thanks Robert M. Corrigan and his work in “Rodent Control: A Practice Guide for Pest Management Professionals” for his input to this article.