Why Rodents Are a Year-Round Threat for Commercial Properties

For many property owners and facility managers, rodents have traditionally been considered a seasonal challenge; a fall and winter issue driven by colder weather and reduced outdoor food sources. But increasingly, commercial properties across the country are experiencing rodent pressures throughout the entire year. Mice and rats are no longer simply entering structures for temporary shelter; they are establishing themselves as full-time residents.

Understanding why this shift has occurred and what facility teams can do to proactively reduce risk is essential to maintaining healthy, compliant, and operationally efficient buildings.

What’s Driving Year-Round Rodent Activity?

Rodents have always lived near humans, relying on our food, waste, and structures for survival. What has changed is how consistently they are able to access these resources, thanks to evolving property uses and expanding urbanization.

Three primary drivers explain today’s increased rodent pressure:

Urban Growth and Habitat Displacement

• Former rural areas are now retail centers, office complexes, and warehouses.
• Conversions of older buildings into new uses disrupts what can be long-established rodent colonies.
• Rodents are forced to relocate and quickly adapt to human environments.
• Access to structures reduces natural stressors like predators and cold weather.

Conducive Conditions Inside Buildings

• Interior heating, ventilation, and equipment keep rodents warm year-round.
• Continuous access to food and moisture supports ongoing reproduction.
• More rodents competing for limited outdoor food sources pushes them to seek new sources inside structures.

 Human Behavior and Activity Patterns

• Increased take-out packaging and outdoor dining have created more opportunities for rodents to access food waste.
• Even buildings whose function is not a restaurant or food service facility—such as office buildings and retail spaces—can offer food sources, including snacks left in desks, vending machines, break rooms, etc.

The result is not necessarily that rodents are moving into structures earlier or staying longer, but that more rodents are living closer to buildings all year, ready to exploit any weakness in sanitation or structural integrity.

Property Type Can Influence Risk

The risk of rodent activity isn’t the same across every property. Factors such as building design, age, maintenance, operations, and surrounding environment all play a role in determining a structure’s rodent vulnerability.

Rodent threat levels also vary based on facility type:

Rodent control in multi-tenant properties such as strip malls and mixed-use developments presents unique challenges. These connected spaces often share walls, ceilings, loading areas, and utility lines—ideal pathways for rodents to move undetected between businesses.

A problem originating in one unit, such as a restaurant or grocery store with abundant food or storage, can quickly spread to neighboring tenants, undermining even the most diligent sanitation and exclusion efforts.

Effective prevention in these environments requires a cooperative, property-wide approach. Regular inspections of all tenant spaces, including those not currently reporting pest activity, are essential to identify vulnerabilities early.

Equally important is maintaining access to shared areas like roof voids, service corridors, and utility chases where rodents often travel. Without clear communication and coordinated inspections among property managers, tenants, and pest management professionals, even well-executed control programs can be compromised by unseen activity just a few feet away.

Rodent Access Points Are Easy to Miss

Rodents are persistent and highly capable explorers in and around commercial properties and can gain entry through small openings that are not always easily visible. For example, mice can enter through a 1/4-inch gap and rats only need a 1/2-inch gap to gain access.

And they are not limited to ground-level entry. Roof rats—a species found across the Southern tier and West Coast of the United States—commonly access structures by:

• Running along overhead wires and utility lines
• Entering through roof vents, HVAC penetrations, and drainage openings
• Using untrimmed trees and climbing vegetation to reach upper floors
• Climbing up the sides of brick, stucco, or other buildings with textured siding

Routine inspections by building maintenance often focus on sidewalks and doorways, but rooftops, parapets, and upper penetrations may pose the greatest vulnerabilities.

What Facility Managers Can Do: A Proactive Defense Strategy

A shift in rodent behavior requires a shift in rodent prevention strategies. Waiting until rodents are inside the building nearly always results in higher costs, greater disruption, and increased health risks.

Property owners and managers can significantly reduce exposure by implementing four core prevention priorities:

1. Improve Sanitation and Waste Handling

• Close dumpster lids consistently
• Clean drain areas and compactors frequently
• Eliminate loose debris and standing water
• Standardized tenant food-storage and cleanup policies

2. Strengthen Building Exclusion

• Seal any opening 1/4 inch or larger with durable materials
• Inspect around utility penetrations, dock plates, door seals, and foundation joints
• Recheck after freeze-thaw or hot-cold cycles that widen gaps and can cause caulk to break down
• Include roofs, eaves, and ventilation housings in inspection routes

3. Maintain Landscaping 

• Trim branches away from structures
• Remove dense vegetation that creates harborage near the foundation
• Keep exterior lighting and signage wiring protected to prevent travel pathways

4. Coordinate Across Shared Spaces

Rodents do not recognize property lines or lease agreements. Effective control depends on cooperation:

• Request inspection access to tenant suites when activity is detected
• Communicate structural or sanitation corrective actions clearly to your pest control service provider
• With the help of your pest control service provider, document shared issues in strip malls, business incubators, and mixed-use sites

Focus on Root Cause, Not Just Bait Stations

While rodent control products and devices are essential, they are only effective when coupled with a proactive inspection-driven strategy.

A strong rodent management program should have your pest control service provider focus on performing regular inspections (30-40% of their time) and exclusion. If the approach focuses only on exterior bait stations, without understanding why rodents are there, the problem will continue.

An effective rodent control program will:

• Identify and correct structural vulnerabilities
• Track rodent activity pathways across the entire property
• Adjust tactics as conditions, weather, and tenant behaviors change
• Have documentation easily accessible

Staying Ahead of a Persistent Threat

Rodents are no longer seasonal invaders; they are constant competitors for the resources available in and around commercial buildings. Commercial property owners and managers who follow strong sanitation protocols, educate tenants, stay on top of maintenance issues and work closely with their pest control service provider can stay ahead of this challenge.

Proactive rodent management protects buildings, reduces cost and disruption, improves occupant experience, and strengthens the long-term value of the property.