How Are Rats Getting Into Our Office Building?

By Chris Williams on January 26, 2013.

rats in the officeQuestion:

I’m the head of maintenance for a small office building. Much to my horror, two of our office workers have reported seeing rats, one in the compactor room and one in the break room upstairs. Our pest control contractor will be treating for rats but I need to know where and how they got in and what they could be feeding on. Any advice would be appreciated.


As you probably know, mouse problems are fairly common inside office buildings but rat problems are not. Nevertheless, sometimes rats will be found causing problems inside office buildings, and occasionally causing great excitement when they appear in halls or offices. You’ve partially answered two important questions: First, where are they active and concentrated? Second, where are they feeding? But most important for long-term control, we need to determine how they are getting inside?

Office buildings provide rats with easy movement laterally since the rats can run horizontally through suspended ceilings and sometimes inside raised floors or utility conduits. Rats can also move up and down from floor to floor inside hollow columns and boxed-in utility runs. Rats in office buildings cause significant damage by chewing on wires, shredding stored materials, and damaging equipment such as computers and telecommunications systems.

Rat Activity Areas

Rats will never be evenly distributed in an office building. Some of the major rat activity areas will be known: Where there have been sightings by office workers, where droppings have been seen, and where workers hear rats scrambling in the walls and ceilings. But rats regularly travel hundreds of feet. Your pest control contractor will need to conduct a systematic inspection of the building to plot out on a floor plan all activity areas (rat runs, nest sites, feeding sites).

Feeding Areas

Rats eat many things but are usually attracted into buildings by an availability of people food. Identify all food sites in the building. If there is a restaurant or cafeteria, that is a likely feeding site, as is any place that contains people food such as food trash storage areas (your compactor room), food storage areas, and office lunch rooms, or the break room that you mentioned. Some office buildings have stores on the ground floor (drug stores, one-stop shops, etc.) that may be providing food.

Rat Entry

In many ways, how rats are getting in can be the hardest question to answer. Rats may be getting into office buildings through underground conduits, sewers, and other invisible routes. More likely, however, they are entering through typical entry sites such as the loading dock, open doors, holes and cracks in the foundation and walls, roof access, and the like. You must find entrances and rat-proof the building or the pest control program will just be an ongoing harvest, new rats will continuously enter, and you will never have long-term relief.

Work closely with your pest control company. Follow the technician on his inspection so you can see the problem sites that he points out and you can direct him to possible entry points that he may not know about.



We’re not satisfied until you are. Learn More