Different Roaches Prefer Different Levels in a Building
By Chris Williams on March 13, 2012.
Q. I have a friend that lives in the basem*nt level of our apartment building. She often gets these gross, large black co*ckroaches (she calls them waterbugs) in her apartment and sometimes sees them in the hallway. I’ve never seen black co*ckroaches on my second floor, but I have seen a few of the little German co*ckroaches in my apartment. Should I expect to get black co*ckroaches in my apartment eventually?
A. No, I don’t think you need to worry about black co*ckroaches invading your apartment. Believe it or not, co*ckroaches do tend to stratify themselves within a building with different species occupying different sites and even different levels. The black co*ckroaches that you have on the basem*nt level are oriental co*ckroaches. They are commonly found only on the lower levels, in cellars, crawlspaces, basem*nts, garages, or near floor drains or water pipes. This roach likes cool dark, damp, poorly ventilated areas. In warm weather, the oriental co*ckroach is often found outside around building foundations and enters through basem*nt doors, crawlspace vents, window wells, and other openings. Oriental co*ckroaches are rarely found above the basem*nt level of a building.
Moving up, you often find the large American co*ckroach occupying the ground floor or lower level of a building. American co*ckroaches are uncommon in residences but can be very common in commercial buildings like bakeries, greenhouses, and restaurants. They are found on the ground floor in boiler rooms, vending machine rooms, storage rooms, garbage rooms, sewers, and near steam pipes. The American co*ckroach sometimes visits the oriental co*ckroach on the basem*nt level but it rarely travels above the first floor.
The familiar German co*ckroach, our most common co*ckroach pest, occupies the upper floors of a building. The German co*ckroach is usually found above basem*nt level and is most common in the kitchen or bathrooms of residences, behind cabinets or appliances. It lives in warm, dry, protected areas but with direct access to food and water. Sometimes the brownbanded co*ckroach can be found in the same sites. This roach is found in drier areas on upper levels. Because it doesn’t require as much moisture as the German co*ckroach, it is more likely to be found away from kitchens and bathrooms, invading bedrooms and living rooms instead.
This ability to separate out and occupy different niches is just one more thing that makes co*ckroaches so successful. They don’t have to compete with other co*ckroach species for habitat and food; they each have their own preferred sites. Of course, there are always exceptions to these multi-level roach rules. For instance, the German co*ckroach can often be found anywhere in a building if conditions are right.
