Which type of cockroach is commonly referred to as a water bug?

The term "water bug" is often colloquially used to refer to both the American and Oriental cockroaches. This designation arises from their affinity for moist habitats and their larger size compared to other cockroach species.

The American cockroach typically lives in warm, damp environments, such as basements, sewers, and bathrooms, which leads to its association with water. Similarly, the Oriental cockroach, also known as a "black beetle," prefers dark and damp locations. Both of these species are frequently found in settings where water is present, contributing to the common reference of them as water bugs.

Unlike the German cockroach, which is small and prefers higher indoor areas with limited moisture, the American and Oriental cockroaches are larger and more directly associated with wet environments. Therefore, the answer highlights the connection between the habitat preferences of these two specific cockroach species and the name “water bug.”