The Cheese Stands Alone
If feathered friends from above aren’t a problem, look underfoot for uninvited guests.
“Rodents are adept at finding and pillaging anything edible and contaminating food sources with their droppings and urine. According to the CDC, rats and mice spread over 35 diseases to humans, both directly and indirectly,” says Hansen.
One reason rodents are difficult to address is because you may not have full access to your building, says Stern. You may be one of many tenants or have structures below your building that aren’t within your purview, sanitation that’s outside of your jurisdiction, or another property attached to your space.
Mice and rodents are also quite comfortable in places that humans tend to avoid – in and around sewer drains, dumpsters, dark underground tunnels, basements, dock areas, and roofs – making their removal a potentially dirty task.
Rodents don’t need a large opening to sneak into your building. If you can fit a pencil under a door or in a crack, a mouse can fit through, Hedges explains. A small rat can use an opening the size of a dime, while a large one can use a hole the width of a quarter. Any area that emits light, like under a door, can also be used as an entrance.
Your landscaping could be a culprit as well. Rodents like to burrow in mulch and soil. You can bury wire under the dirt that will act as a barrier to rodents without harm to your plants, says Stern.
“If you have large trees with branches touching the facade or roof, you’re giving rodents a natural pathway onto your building. Cut branches a minimum of 6 feet back from the wall,” Hedges recommends. “Make sure shrubs grow upward and don’t have ground-hugging coverage to eliminate another potential hiding spot.”
If rodents become a problem despite your best effects, traps are your next line of defense. Snap traps are chemical-free and there are many humane models that kill the mouse or rat instantly, as opposed to a glue board that allows the rodent to die of starvation.
“Mechanical traps also provide a body count so you can see the results of your efforts,” Stern says. “If you use poisons, you may not know how effective the trap is. Rodents will leave the bait site and die elsewhere, creating disposal and sanitary issues.”
“As a preventive measure, however, try using tamper-resistant bait stations on the exteriors to discourage rodents from entering the facility in the first place,” adds Hedges.
Natural repellants such as cayenne pepper gels can also be used to move rodents from critical areas to another that’s more suitable for traps. This approach is particularly ideal for kitchens, food storage, or healthcare settings.
Sound waves are another humane method and use sonic or ultrasonic frequencies to drive mice away from a space. These work well as a temporary approach, but should be complemented by additional strategies.
“Sound devices do repel rodents, but pests can also adjust to noise levels because the urge for food and habitat can be stronger than the annoyance,” Stern observes. “Sonic units are certainly one of many tools you can use, but they’re not going to resolve the issue completely.”
No matter which devices you use, it’s imperative to have a year-round rodent program, emphasizes Harrison. “You will always face rodent pressure. Are you or your pest control provider routinely filling in gaps, baiting around dumpster areas, and performing inspections to look for burrowing?”
An Ounce of Prevention
How much do you have set aside in your annual budget for preventive pest control?
Facility managers can make pest prevention a priority with many low-cost strategies. Make visual inspections a routine part of your maintenance program and implement simple fixes like door sweeps, good cleaning habits, and proper food storage.
For existing pests, costs are difficult to calculate because each building is unique. Factors that affect pricing are the type of pest being addressed, square footage of your building, extent of the infestation, equipment rental (such as scaffolding or lifts), materials, and labor. Some properties may be able to resolve their infestation with an inexpensive solution such as bird spikes or rodent traps, but other tactics may be required if the problem persists.
The most cost-effective strategies are always the ones that prevent unwanted guests from making your building their home in the first place.
Jennie Morton firstname.lastname@example.org is associate editor of BUILDINGS.