While the German cockroach is certainly the most difficult roach pest species to eradicate from homes and buildings, they are not necessarily the most revolting roaches in your neighborhood, as the much larger American cockroach species prefers to dwell in habitats that other roaches would find just a bit too filthy for their taste. For example, American cockroaches are found congregating in sewers more often than any other roach species. Unfortunately, this means that American cockroaches frequently travel directly into homes from their favored septic habitat via sewer pipes. So if you have ever wondered why one, or several 2 inch cockroaches were meandering within your sink, bathtub or around your basement drain, you now have a plausible explanation.

American cockroaches are the largest of all cockroach pest species in the US, and they will eat just about anything, but they have a particular taste for fermented foods and beverages, especially beer. In addition to being the annoying drunks of the roach community, American cockroaches are, not surprisingly, the filthiest of all roach pests. One study found that American cockroaches carry numerous disease-causing species of bacteria including Klebsiella, Pseudomonas, Escherichia coli, Staphylococcus, Proteus and Streptococcus. The study’s authors found that 90 percent of the American cockroaches that they had collected were carrying at least one of the above named species of bacteria. Another study found 22 species of pathogenic human bacteria, viruses, fungi, protozoans and five species of Helminithic worms covering the bodies of numerous American cockroach specimens. The study’s authors attributed the American cockroaches’ filthy exterior to their preference for sewer habitats. Yet another study found that American cockroaches are genetically designed to survive pathogen-rich sewer systems. One documented report describes a “black geyser” that erupted from a classroom sink. Upon closer inspection, the children and teacher became horrified upon learning that the geyser was, in fact, a massive amount of cockroaches. The school’s pipes were later found to be infested with the pests.

American cockroaches tend to emerge from indoor drains that have become dry due to a long-lasting lack of water flow. Regularly allowing water to flow into sink, tub and even toilet pipes will prevent the pests from journeying into your home. Also, using window screens to cover vent pipes on household roofs will prevent American cockroaches from gaining access to attics after the pests travel up sewer pipes.

Have you ever spotted cockroaches around an indoor drain?