The office building where I work has a break room/vending room on the basement level. Lots of us eat our lunch there and we’ve noticed cockroaches running around, but these are HUGE cockroaches, much bigger than any I’ve seen in apartments. Do office buildings have their own breed of cockroaches!? R. P., North Andover, MA

You’re probably talking about the American cockroach, and yes it is big, about 1-1/2 inches long (see Do the Roaches Suddenly Seem Bigger?). Compare that to our common pest cockroach, the German cockroach, which is slightly more than1/2 inch long. American cockroaches are a reddish-brown color and they can fly, although you rarely see them do so indoors.

Commercial and Retail Accounts Have the Biggest Problem

American cockroaches are primarily pests in our commercial accounts, although they do sometimes occur in lower levels of multi-unit apartment buildings. We often find them in subfloor or ground floor levels of office buildings, and they can become real pests in commercial establishments that handle food such as bakeries, restaurants, breweries, and grocery stores. They are also pests in greenhouses and sewers.

The lower levels of office buildings are perfect environments for American cockroaches because they like it warm, dark, and damp. Besides your break room, you could probably find them in the parking garage, in utility tunnels, in storage areas, in boiler rooms, trash rooms, or near steam pipes and boilers.

Sewers Can Be a Source of American Cockroaches

The fact that American cockroaches are the most common roaches in sewers is another reason that they end up in commercial buildings (see Cockroaches From Sewers). When populations get high or if a sewer line backs up, the cockroaches vacate and can end up in buildings. They can also follow sewer pipes and enter lower levels through dry floor drains. In the fall, American cockroaches sometimes leave the sewer system and will move into homes as well (see American Cockroaches Can Move Indoors in Fall).

I assume your building has a pest control contractor. Maybe the exterminator isn’t aware of the extent of the problem. You definitely don’t want cockroaches in the same space where you are enjoying food and drink. If they’ve wandered in from the sewer system, imagine the germs they are carrying on their bodies as they walk across tables and dishes. Make sure your building manager is aware of the problem.

By Termiteman (Own work) [GFDL or CC BY 3.0], via Wikimedia Commons

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