What is a common sign of a German cockroach infestation?

A common sign of a German cockroach infestation is the presence of two stripes on the thorax. This characteristic physical trait is one of the easiest ways to identify the German cockroach compared to other species. The two distinct dark stripes running parallel on their light brown body are reminiscent of a saddle or a racing stripe, making it a key identifier when assessing a potential infestation.

While other options may involve signs typically associated with cockroaches or pests in general, they do not specifically point to a German cockroach infestation. For example, a smell of rotten food could indicate a variety of pest issues, and while the presence of wings may be noted in some cockroach species, it's not a reliable indicator of the German cockroach, which is often found in its swift crawling phase more than in flight. Additionally, large droppings would more commonly relate to larger species of cockroaches, whereas German cockroach droppings are small and dark. Thus, the definitive identification of the species through its thoracic stripes is a crucial aspect of recognizing a German cockroach problem.